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Staying Healthy on Plant-Based Diets
    (Formerly Known As Staying a Healthy Vegan)

by Jack Norris, RD

Contents
Introduction
I was vegan for awhile, but...
A Candid Discussion About the Vegan Diet
Position of the American Dietetic Association
Summary of Health Benefits of a Vegetarian Diet
U.S. Vegetarians Health: Latest data from the Adventist Health Study
Current State of Vegan Health
Diet and Cancer
Nutrients that Need Attention in Vegan and Vegetarian Diets
Vitamin B12
Fats
Saturated Fats
Trans Fats
Monounsaturated Fats
Polyunsaturated Fats
Omega-6 Fats
Omega-3 Fats
Polyunsaturated Fat Recommendations
Nutrients that Need Attention in Vegan Diets
Calcium
Vitamin D
Iodine
Miscellaneous Nutrients
Protein
Vegans Might not Meet Protein Needs If...
Non-Protein Amino Acids
Taurine and Carnitine
Creatine
Iron
Zinc
Selenium
Vitamin A
Other Nutrients & Multivitamins
Pregnancy
Infants
Children
Benefits of Selected Vegan Foods
Summary of Daily Suggestions for Vegan Adults
Vegan Multivitamins
Footnotes
Introduction

For ease in discussion, the following dietary categories are defined:

Although lacto-ovo vegetarianism has been around for most of human history, the vegan diet appears to be a relatively new experiment - only since the mid-1940s has it been practiced in an organized fashion in the Western world. So far, the experiment appears to be successful: vegans in developed countries have been shown to have the same overall mortality rates as meat-eaters with healthy lifestyles (low smoking and alcohol intake).2 These mortality rates (deaths per year before age 90) are about 50% lower than those of the general population.2 However, there are areas where vegans' health can be improved.

This article has three purposes:

I also wrote this article to provide information that other Vegan Outreach members and I wish we had known when we became involved in promoting veganism.

I was vegan for awhile, but...

Vegan Outreach promotes a vegan diet in order to lessen the suffering of animals. Since the average American consumes thousands of animals over the course of a lifetime, each person who eats a vegan diet makes a difference by removing their support from the factory farming and slaughtering of these animals. For this reason, I have been involved in vegan advocacy since 1989.

During my years of outreach, I have been told by many people that they tried to be vegetarian or vegan, but hadn't felt healthy. I found this troubling. How can we prevent animal suffering by promoting a vegan diet for our entire society if some people do not respond well to it? Finding an answer to this problem was a major motivation for my becoming a Registered Dietitian. In researching the subject, I discovered that some claims about the vegan diet include distortions or omissions which can lead to people having poor experiences.

For example, some vegan advocates emphasize that humans need only small amounts of B12 and that it can be stored in the body for years. It is true that, at the time they become vegan, some people have enough B12 stored in their liver to prevent serious B12 deficiency for many years. However, people often misinterpret this to mean that you only need to consume a tiny amount of B12 once every few years. Actually, to build up such stores, it takes many years of consuming B12 beyond one's daily needs. Many people do not have large enough stores of B12 to be relied upon even for short periods. This is an easy problem to solve by simply eating B12-fortified foods or taking a supplement.

Nutritional myths have a way of going from one extreme to the other. For example, people once believed that in order to rely on plant protein, you had to combine particular foods at every meal. We now know this is not true. But in countering this myth, claims have gone from "You don't need to combine proteins," to "It's easy to get enough protein on a vegan diet;" to the harmful "It's impossible not to get enough protein!"

On average, vegans get enough protein. In fact, many people trying a vegan diet may choose foods that are high in protein without knowing it. Others may randomly choose foods that are not high in protein. Personally, since I do not feel right when I'm not eating quite a few protein-rich foods each day, I can see how someone else might be ready to quit a vegan diet after a few days of not consuming some protein-rich foods. I fear that many people quickly give up on a vegan diet, thinking it made them feel bad, instead of realizing they might have felt differently had they eaten more protein-rich foods.

This is not to say that every person does better with more protein. Some people report feeling better eating less protein. There are many differences among people and how they respond to various foods.

Eating enough calories might be an issue for an uninformed person who decides to give the vegan diet a try for a few days. Someone on the standard Western diet may only be aware of vegan foods that are low in calories (e.g., salads, vegetables, fruits). Eating only these foods for a day might leave someone unsatisfied and thinking the vegan diet is to blame, when all they needed to do was eat more high-calorie foods.

Again, not everyone needs calorie-dense foods. Some people enjoy the fact that when eating low-calorie foods, they can eat more frequently and a higher volume than ever before without gaining weight; and feel more energetic doing so.

Of course, many advocacy groups are actively trying to educate people about the wide variety of satisfying vegan foods. In promoting the diet, each person could help prepare potential vegans for the real possibility that they won't feel good if they don't choose some calorie-dense foods.

Less noticeable problems can arise due to misinformation. One can find certain studies that support the idea that meat, eggs, and dairy are the cause of osteoporosis, and that calcium intake is not important. Because the arguments can sound impressive, someone might take these claims as fact. Such a person might conclude that a vegan diet must protect against osteoporosis, and that there is no need for vegans to make sure they are getting plenty of calcium and vitamin D. However, selectively choosing such studies leaves out the majority of research published on the subject. Someone who evaluates more of the research will likely conclude that vegans, like non-vegans, should ensure good sources of calcium and vitamin D on a daily basis.

The other nutritional issues of which vegans should be aware are addressed later in this article.

A Candid Discussion About the Vegan Diet

Few long-term, scientific studies have looked at true vegans. A summary of the research on vegetarians and vegans is included in this article. The research has not overwhelmingly supported the idea that a vegan diet is vastly superior to a diet that includes meat or a lacto-ovo vegetarian diet, and some vegans have found this to contradict what they have always heard. How can this be explained?

Popular vegan literature has sometimes presented studies on groups -- such as lacto-ovo vegetarians, semi-vegetarians, cultures that eat little meat, and people who have a high intake of fruits and vegetables -- as indications of the health status of vegans. Although this can provide some useful information about some aspects of the vegan diet, it cannot substitute for studying actual vegans.

Additionally, certain risk factors, such as cholesterol levels, have been used to make projections about the health of vegans, but these do not necessarily tell the whole story. For example, while vegans' cholesterol levels tend to be low, some vegans' low vitamin B12 status can potentially increase their risk for heart disease and stroke. This is easily solved by ensuring a consistent source of B12.

For a concise explanation of the different types of studies and their pros and cons, please see my article, Nutrition Research: What You Should Know.

There are real differences in how people respond to various diets. While many people thrive on a vegan diet, it may not be so easy for others. When someone is committed to reducing animal suffering, there are often solutions to these dilemmas. Affirming everyone's experience is the first step in working with people towards a more humane diet.

I would like to see vegan advocates promote the diet in such a way that we minimize the chances of someone having a bad experience. In so doing, I hope that future, long-term studies on vegans will show us to have even better health than our meat-eating counterparts. Promoting veganism as though there are no nutritional concerns may initially attract more people; but we don't want people merely to go vegan -- we want them to stay vegan.

Position of the American Dietetic Association and Dietitians of Canada: Vegetarian Diets

In their 2003 Position Paper on vegetarian diets, the American Dietetic Association and Dietitians of Canada state, "Well-planned vegan and other types of vegetarian diets are appropriate for all stages of the life cycle, including during pregnancy, lactation, infancy, childhood, and adolescence. Vegetarian diets offer a number of nutritional benefits, including lower levels of saturated fat, cholesterol, and animal protein as well as higher levels of carbohydrates, fiber, magnesium, potassium, folate, and antioxidants such as vitamins C and E and phytochemicals. Vegetarians have been reported to have lower body mass indices than nonvegetarians, as well as lower rates of death from ischemic heart disease; vegetarians also show lower blood cholesterol levels; lower blood pressure; and lower rates of hypertension, type 2 diabetes, and prostate and colon cancer."30

Summary of Health Benefits of a Vegetarian Diet

Health Benefits of a Vegetarian Diet, a 1999 paper co-authored by experts on the mortality rates of vegetarians, concludes:

Compared with non-vegetarians, Western vegetarians have a lower mean BMI (by about 1 kg/m2), a lower mean plasma total cholesterol concentration (by about 0.5 mmol/l [19 mg/dl]), and a lower mortality from IHD [ischemic heart disease] (by about 25%). They may also have a lower risk for some other diseases such as diverticular disease, gallstones and appendicitis. No differences in mortality from common cancers have been established. There is no evidence of adverse effects on mortality. Much more information is needed, particularly on other causes of death, osteoporosis, and long-term health in vegans.12
U.S. Vegetarians' Health: Data from the Adventist Health Study1

The Adventist Health Study is the only major study on the general health and mortality of vegetarians in the U.S. Many members of the Seventh-day Adventist Church are vegetarian. Here are some details:

Results were:

  Men Women
Vegetarians Non-vegetarians Vegetarians Non-vegetarians
BMI 24.3 26.2 23.7 25.9
Heart disease 38% Lower for Men   No Difference for Women  
Overall mortality Lived 3.21 more yrs   Lived 2.52 more yrs  
BMI - Body Mass Index. A measure of healthy body weight. Lower than 20 is underweight, while ≥ 25 is overweight.

Compared to the non-vegetarians, vegetarians had about:

Life expectancies in the Adventist Health Study were published in 2001.27 They showed that white, non-Hispanic Seventh-day Adventists live longer than other white Californians (7.28 years for men, 4.42 years for women). According to the researchers, this group of Seventh-day Adventists were the longest-lived, formally studied population in the world (with an average life span of 78.5 years for men, 82.3 for women).

The following variables were shown to increase life expectancy:

The only other variable looked at was hormone replacement therapy for women which possibly contributed to increased life expectancy.27

Vegetarian Mortality Rates

In 1999, data were published from the 4 largest studies (including the Adventist Health Study mentioned above) analyzing vegan mortality rates.2 The data compared the risk of dying from various diseases between people with different diets but who had similar lifestyles. The standardized mortality ratios (SMR) in 3 of the studies showed less mortality in these groups than in the population at large (no SMR was calculated for the 4th study). Most of this difference was thought to be due to lower smoking rates in the study groups, but some difference may have been due to a generally healthier diet overall than in the population at large.

Compared to 31,766 people who ate meat at least once per week:

Click here for the article The Long Term Health of Western Vegetarians, by Paul Appleby of the European Prospective Investigation into Cancer and Nutrition (EPIC) Study.

Diet and Cancer

It may come as a surprise that vegetarians have not been shown to have lower rates of mortality from cancer. There has not been enough data on vegans to determine their cancer rates. For a recent summary of the evidence regarding diet and cancer, see Diet, Nutrition and the Prevention of Cancer, by Key TJ, Schatzkin A, Willett WC, Allen NE, Spencer EA, Travis RC. of the Cancer Research UK Epidemiology Unit. An earlier version of this paper is The Effect of Diet on Cancer, by Key TJ, Allen NE, Spencer EA, and Travis RC of the Cancer Research UK Epidemiology Unit.

Nutrients That Need Attention in Vegan and Vegetarian Diets

Jump to Summary of Recommendations for Vegan Adults.

The acronym "DRI" is used a lot in this article. It stands for Dietary Reference Intake which, to make a long story short, for practical purposes should be thought of as the new term to replace Recommended Dietary Intake (RDA).

Vitamin B12

There are no reliable, unfortified plant sources of vitamin B12 (See B12 in Tempeh, Seaweeds, Organic Produce, and Other Plant Foods for more information); therefore fortified foods and/or supplements are necessary for the optimal health of vegans and even vegetarians in many cases. Luckily, vitamin B12 is made by bacterial fermentation such that no animal products are necessary to provide it.

There are two types of B12 deficiency: mild and overt.

Overt B12 Deficiency:

Mild B12 Deficiency:

If you have been a typical meat eater for most of your life, your body should have stored enough B12 to prevent overt deficiency for a number of years. However, when B12 intake is zero, old B12 stores cannot be relied on to keep homocysteine levels in check.

Vegan infants get B12 through breast milk (their mothers must have a consistent B12 intake) or formula.

The DRI for vitamin B12 is 2.4 micrograms for adults.

B12 Recommendations

Step 1

    If you have not had a regular source of B12 for some time, buy a bottle of 1,000 g (or greater) B12 tablets. The following (and many others) are vegan:

    • Pangea VeganLife B12 Chewable Supplement 1,000 mcg tablets
    • VegLife sublingual 1,000 mcg lozenges. Sold in stores (website has a store locator).
    • Freeda Vitamins 500 mcg lozenges
    • Nature's Bounty sublingual 2500 mcg
    • Solgar sublingual 1,000 mcg nuggets

    Place 2,000 g under your tongue until the tablet(s) has dissolved, once a day, for 2 weeks. You can break the remaining tablets in half or quarters for Step #2. It's okay to take more than recommended. Then follow the advice under Step #2.

Step 2

    If you have had a regular source of B12, skip Step 1. One of the following daily recommendations should maximize your B12 status:

    • 1.5 - 2.5 g, twice a day, from fortified foods or supplements1
    • 10 - 100 g, once a day, from a supplement1,2

Notes

  • In foods, B12 is measured in micrograms (aka "g" or "mcg"). 1,000 g = 1 mg.
  • The DRI for vitamin B12 is 2.4 micrograms for adults.
  • Fortified foods: Amounts listed on a nutrition label are based on 6 g/day. For example, 25% of the Daily Value = .25 * 6 g = 1.5 g.
  • Do not rely on any seaweed (e.g., algae, nori, spirulina), brewer's yeast, tempeh, or "living" vitamin supplement that uses plants as a source of B12.
  • Do not rely solely on one type of fortified food such as Red Star Nutritional Yeast.
  • Vegan infants: The Institute of Medicine recommends that infants of vegan mothers be supplemented with B12 from birth because their stores at birth and their mother's milk supply may be low.3
  • Exceptions: People with digestive or malabsorption diseases (such as pernicious anemia), chronic kidney failure, B12 metabolism defects, or cyanide metabolism defects should consult a bona fide health professional.
  • Cigarette smokers should consider a non-cyanocobalamin source of B12. Click here for more information.

Click here for an explanation of how these recommendations were formulated.

Footnotes for Recommendations for Vegans and Near-Vegans
1. Lower limit based on minimum recommendations in What Every Vegan Should Know about Vitamin B12.
2. In a single dose, B12 absorption drops to 1-1.5% for the amounts above 5 g.
3. Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline. Washington, DC: National Academy Press; 2000.

See Vitamin B12: Are You Getting It? for more information about B12.

Fats

Below is a quick summary about fats simply gives basic recommendations. For a more comprehensive discussion see The Challenge of Defining Optimal Fat Intake by Virginia Messina, MPH, RD, and Making Sense of Fats and Oils by Brenda Davis, RD.

Saturated Fats

  • Many saturated fats raise the risk of heart disease.
  • Found in high amounts in animal products; also in high amounts in coconut and palm kernel oils.
  • Because saturated fats are stable at high temperatures, they are often used for deep-frying. You should limit deep-fried foods, but if you are going to fry foods at high temperatures, palm oil, which is mostly saturated, may be the best choice for its stability.

    Trans Fats

  • Found mostly in foods made with hydrogenated or partially hydrogenated oils, including margarines, shortening, commercial frying fats, crackers, cookies, and other snacks. Check label. Butter and animal fat can also contain trans-fats from bacterial fermentation.33
  • The consensus among nutritional professionals is that trans fats increase the risk of heart disease and many other diseases.
  • Two vegan margarines without hydrogenated oils are Soy Garden and Earth Balance, available at many natural foods stores.

    Monounsaturated Fats (MUFA)

  • Also known as omega-9 fats, n-9, or oleic acid.
  • Improve cholesterol levels.
  • Abundant in olive oil, canola oil, high oleic sunflower oil, hazelnut oil, high-oleic safflower oil, and almond oil.
  • Olive may be the best oil for cooking at moderate temperatures. It is not as refined as other oils, making it a reliable source of vitamin E and possibly other healthy components. It has stood the test of time, as the primary oil used in the healthy Mediterranean diet. If you do not like the taste of olive oil in some dishes, try other oils made of high MUFA. See chart.
  • Avocados and many nuts (almonds, cashews, filberts/hazelnuts, macadeamias, peanuts, and pecans) are high in MUFA. Because nuts are high in nutrients and other protective compounds, you can benefit from eating them on a daily basis.

    Polyunsaturated Fats (PUFA)

    There are two main families: omega-3s and omega-6s.

      Omega-6s (n-6)

      • Building blocks for hormones that increase inflammation and blood clotting.
      • LA (linoleic acid)
        • Most prevalent omega-6 in plant foods. Found in corn, sunflower, "vegetable," soy, and safflower oils.
        • Since most vegetarians get plenty of omega-6 fats38 they should limit these oils, especially in cooking.

      Omega-3s (n-3)

      There are 3 important n-3 fatty acids:

      1. ALA (alpha-Linolenic acid; aka LNA)
        • Found mainly in flaxseeds and oil, hemp seeds and oil, camelina oil (aka Gold of Pleasure), walnuts and oil, canola oil, soybeans and oil. Also found in leafy green vegetables and other plant foods, but not in large enough amounts to contribute significantly.
        • Reduces blood clotting, improves artery flexibility, and may also reduce heart arrhythmias. LNA shows a strong association with reduced cardiovascular mortality rates, including those from heart attack and stroke.
      2. EPA (eicosapentaenoic acid)
        • Found mainly in fatty fish. Also in irish moss and wakame, but the ratio of iodine to EPA is much too high to make these foods a recommended source.
        • Precursor for eicosanoids (hormone-like substances that act on local tissues) which reduce inflammation, blood clotting, and cholesterol.
      3. DHA (docosahexaenoic acid)
        • Found mainly in fatty fish and seaweed.
        • Major structural component of the gray matter of the brain, the retina of the eye, and cell membranes.
        • Low levels of DHA have been associated with depression.

      For some of its benefits, LNA must be converted to EPA which in turn must be converted to eicosanoids or DHA. DHA can also be retroconverted into EPA at a rate of about 10%.36 Although there is no clear evidence that vegans require supplements of DHA or EPA, vegan supplements of DHA are available:

      Notes About Flax

      • Flaxseeds are the most concentrated source of ALA.
      • One teaspoon of flaxseed oil contains 2.5 g of ALA.
      • One tablespoon of flaxseeds contains 2.1 g of ALA.
      • If flaxseeds are not ground, there is a chance they will not be digested. They can be ground in a blender (works best with a large amount) or coffee grinder, and then stored in the freezer. Ground flaxseeds can be sprinkled on cereal or used in baked goods.
      • Cooking flaxseed oil damages the ALA, but it can be put on warm food such as toast. Flaxseed oil should be kept in the refrigerator.
      • A straight teaspoon of flaxseed oil does not taste so great. Some people use cinnamon-flavored, tablets, or put it on toast or salad to make it taste better.

      Notes About Camelina Oil

      • Camelina oil is an oil that supposedly has an n-3:n-6 ratio of 3:1. I only recently found out about it and am not sure of the actual ratio - the USDA does not list camelina oil in their nutrient database.
      • Medline lists one study using camelina oil, Effect of alpha-linolenic acid-rich Camelina sativa oil on serum fatty acid composition and serum lipids in hypercholesterolemic subjects (Metabolism. 2002 Oct;51(10):1253-60). In this study, camelina oil fared better than canola (aka rapeseed) and olive oil on LDL cholesterol levels and in increasing EPA and DHA levels.
      • Camelina oil can be purchased at http://www.goldofpleasure.com/. However, please note that this site is a commercial site and so anything said should be taken with some skepticism (particularly their anti-flaxseed oil statements which might give the impression that it's difficult to obtain flaxseed oil that isn't rancid; refrigerated flaxseed oil from the store should be just fine). This site says that camelina oil is stable during cooking and is high in vitamin E.

      Notes About Hemp

      • Hemp seed oil is also a good source but not available everywhere.

      PUFA Recommendations

      Many vegetarians do not get enough omega-3 fats.15 This can result in higher blood clotting which is a risk for heart attack and stroke.

      A panel of experts on omega-3 fats has recommended an n-3 intake for nonvegetarians of about 1.3% of calories.37 They recommended an additional 300 mg/d of DHA for pregnant and lactating nonvegetarians. Limiting n-6 intake and increasing intake of ALA to 1.5% of calories will enhance conversion of ALA to EPA and DHA; however, it can sometimes take a few months of following these recommendations to build up DHA. Based on the Recommended Dietary Allowance (RDA) for caloric intake (and subtracting .5% of kcal for usual intake without any supplementation), the following amounts of ALA should be added to the diet:

      age
      (years)
      ALA
      (g/day)
      flaxseed oil
      (rounded teaspoons)
      0.5-6

      .9 - 2.0

      .5

      > 7

      2.2 - 3.3

      1
       

      PregnantA

      2nd Trimester

      An extra .3

      An extra .5

      3rd Trimester

      An extra .3

      An extra .5

      LactatingA

      extra .6

      extra .5

      A - Pregnant and lactating women should consider
      replacing the extra .5 teaspoon of flaxseed oil
      with 300 mg (.3 g) of DHA because infants have
      more difficulty converting n-3s.

      Limit omega-6 Fats

      Limiting omega-6 intake is important for maximizing the conversion of omega-3s into EPA and DHA. You should aim for an omega-6 to omega-3 ratio of 4:1 or less. The following sources of n-3s are followed by their approximate ratio of omega-6 to omega-3:

      omega-3 source approx. n-6:n-3 ratio
      flaxseeds/flaxseed oil 1:4
      canola oil 2:1
      english walnutsA 4:1 - 5:1
      walnut oil 5:1
      soybean oil 7.5:1
      black walnuts 10:1
      AEnglish are the typical walnuts found in most grocery stores.

      Only the top two foods (flaxseeds and canola oil) fall below the recommended ratio of n-6:n-3. This means that other foods will not help decrease the ratio to 4:1, though walnuts will not harm the ratio much while providing a good source of omega-3s.

      Flaxseed oil goes a long way in correcting the imbalance in a typical vegetarian diet, but you should only take the recommended amounts.

      If you prefer oils on foods such as bread, I recommend raw olive or raw canola oil to minimize your n-6:n-3 ratio as well as for other benefits.

      People with diabetes do not efficiently convert ALA to EPA and DHA and should replace .3 grams of ALA with 300 mg of DHA per day.

      Parents with prematurely-born infants should contact a health professional about supplementing their diets with essential fatty acids.

    Nutrients That Need Attention in Vegan Diets
    Calcium

    Recent, small studies have shown vegans to have the same or slightly worse bone mineral density as non-vegans.5, 6, 7, 8, 9

    Factors that can prevent osteoporosis:

    • Weight-bearing exercise throughout one's lifetime is one of the most important.
    • Adequate calcium, vitamin D, vitamin K, protein, potassium, magnesium, and boron.
    • Adequate estrogen levels (for women)

    Factors that can contribute to osteoporosis:

    • High sodium and caffeine intake
    • Smoking
    • Excessive amounts of, or too little, protein

    Plant foods that provide calcium offer other nutrients that are good for bones: vitamin K in leafy greens; vitamin C, potassium, and magnesium in calcium-fortified orange juice; boron in beans, nuts, leafy green vegetables, and non-citrus fruits.10

    The calcium in kale, broccoli, collard greens, and soymilk is absorbed about the same percentage as that in cows' milk.

    The calcium in spinach, Swiss chard, and beet greens is not well absorbed, due to their high content of oxalates, which bind calcium.

    Many non-dairy milks are now fortified with calcium, vitamin D, and/or vitamin B-12. Many orange juices and other juices are fortified with calcium.

    Shake calcium fortified non-dairy milks before pouring as the calcium can settle on the bottom.

    Calcium supplements can inhibit iron absorption if eaten at the same time.23

    The Daily Value for calcium on food labels is 1,000 mg. Therefore, if a food label says it has 25% of the daily value, it means it has 250 mg of calcium per serving.

    Dietary Reference Intake (DRI) for calcium:

      Age mg Upper Limit*
      1 - 3 500 2500
      4 - 8 800 2500
      9 - 18 1300 2500
      19 - 50 1000 2500
      >50 1200 2500
      *Do not exceed the upper limit.

    Plant foods high in calcium:

      Food Serving Ca (mg)
      cow's milk (for comparison) 1 C 300
      soymilk, fortifiedb 1 C 200-300
      tofu (if 'calcium-set') 1/2 C 120-300
      orange juice, fortifiedb 1 C 250
      blackstrap molasses 1 T 187
      collard greensa 1/2 C 178
      sesame seeds 2 T 176
      veg baked bean 1 C 128
      navy beans 1 C 128
      kalea 1/2 C 90
      broccolia 1/2 C 50
      almonds 2 T 50
      a - Cooked
      b - Read the label for calcium amounts
      T - tablespoon
    Vitamin D

    Vitamin D regulates calcium absorption and excretion, especially when calcium intake is low.

    There is evidence that some cases of fibromyalgia are misdiagnosed vitamin D deficiency.

    Vitamin D can be made by the action of sunlight (UV rays) on skin. Light-skinned, non-elderly adults exposing their hands and face to sunlight during the summer for 10-15 minutes, 2-3 times/week should get enough vitamin D from sunlight. Extra amounts can be stored for during the winter, however, there is some evidence that these stores are not enough for those living in northern climates. See Vitamin D: The Forgotten Nutrient.

      Vegans who do not get much sunlight exposure should supplement with vitamin D, especially during the winter or cloudy months.

      Elderly people may need up to 4 times,18 and dark-skinned people may need up to 6 times, the amount of sun listed above in order to meet vitamin D needs through sunshine alone. Thus, it is prudent to take a modest vitamin D supplement or use fortified foods.

      Vitamin D is not synthesized during the winter in northern climates.10

    The only significant, natural sources of vitamin D in foods are fatty fish (e.g. cod liver oil), eggs (if chickens have been fed vitamin D), and possibly some wild mushrooms.18 Most Americans get vitamin D through sunshine, fortified milk, and fortified margarine.

    Types of vitamin D:

      Vitamin D3 - cholecalciferol; is derived from animal foods or made by the action of ultraviolet light on the skin.

      Vitamin D2 - ergocalciferol; a plant chemical that has vitamin D activity in humans, but not as much activity as D3; therefore vegetarians who rely on D2 may need slightly higher intakes.18

    One small study found an increase in lumbar spine (lower back) bone density in 4 out of 5 vegans in Finland (a northern country where sunlight does not activate vitamin D during the winter) who took 5 mcg/day of vitamin D2 for 11 months.4

    The Daily Value for vitamin D is 10 mcg (400 IU). Therefore, if a food label says it has 25% of the daily value, it means it has 2.5 mcg (100 IU) per serving.

      Dietary Reference Intake (DRI) for vitamin D
      Age (yrs) DRI mcg(b) (IU) Upper LimitA
      mcgB (IU)
      < 1 5 (200) 25 (1000)
      1-50 yrs old (incl. pregnancy) 5 (200) 50 (2000)
      51-70 yrs 10 (400) 50 (2000)
      Over 70 15 (600) 50 (2000)
      A - Do not exceed the upper limit.
      B - mcg = microgram = g

    Sources of Vitamin D:

  • Typical fortified soy, almond, or rice milk: 2-3 mcg (80-120 IU) per Cup
  • Vitamin D-only Supplements:
    • Country Life ergocalciferol: 25 mcg (1000 IU) D2 per tablet (can break in half)
      Sold in many health food stores.
    • Thompson ergocalciferol: 10 mcg (400 IU) D2 per tablet
      Can order at Herbal Hut.
    • Multivitamins containing vitamin D2.
  • Iodine

    Iodine is needed for healthy thyroid function which regulates metabolism. Both too much, and too little, iodine can result in abnormal thyroid metabolism.

    Studies have shown that vegans in Europe (where salt is either not iodized or not iodized at high enough levels) who do not supplement (as well as those who oversupplement) have indications of abnormal thyroid function.19,20

    Iodine is found in produce grown in some parts of the country, but in very small amounts. Iodine deficiency is not as much of a problem for U.S. vegans as it is for European vegans,19,20 whose food supply contains less iodine. North American vegans should take a modest iodine supplement on a regular basis to ensure they are meeting requirements because it's very hard to predict how much is in any given person's food supply. 75-100 mcg every few days should be ample.

    Avoid intakes in excess of the Upper Limit.

      Dietary Reference Intake (DRI) for Iodine
      Age
      (yrs)
      DRI
      (mcgB)
      Upper limitA
      (mcgB)
      1 - 3 90 200
      4 - 8 90 300
      9 - 13 120 600
      14-18 150 900
      > 18 150 1100
      pregnant    
      ≤ 18 220 900
      > 18 220 1100
      lactating    
      ≤ 18 290 900
      > 18 290 1100
      A - Do not exceed the upper limit.
      B - mcg = microgram = g

    Vegan iodine supplements can be found in most grocery or natural food stores. Most vegan multivitamins contain iodine.

    More details on iodine from the UK Vegan Society. An excerpt:

      ...Iodine deficiency during pregnancy and early infancy can result in cretinism (irreversible mental retardation and severe motor impairments).... Hypothyroidism can manifest as low energy levels, dry or scaly or yellowish skin, tingling and numbness in extremities, weight gain, forgetfulness, personality changes, depression, anaemia, and prolonged and heavy periods in women.... Hypothyroidism can also cause carpal tunnel syndrome and Raynaud's phenomenon [episodes of blood flow loss to the fingers, toes, ears, and nose]. Hypothyroidism can lead to significant increases in cholesterol levels and homocysteine levels and is implicated in about 10% of cases of high cholesterol levels. Correcting hypothyroidism can lead to a 30% drop in cholesterol and homocysteine levels.

    And even more on iodine.

    Miscellaneous Nutrients
    Protein

    It was once believed that vegetarians (and vegans) needed to combine protein sources at each meal to get "complete protein." Now we know that protein combining at each meal is not necessary.

    In their Position Paper on Vegetarian Diets, The American Dietetic Association states:

      "Plant protein can meet requirements when a variety of plant foods is consumed and energy needs are met. Research indicates that an assortment of plant foods eaten over the course of a day can provide all essential amino acids and ensure adequate nitrogen retention and use in healthy adults, thus complementary proteins do not need to be consumed at the same meal."

    Experts recommend that adult vegans eat .4 g of protein per day for every pound of healthy body weight.22 Recommendations for younger vegans are:26

      Protein Recommendations for Young Vegans
      Age
      (yrs)
      Females
      (grams/day)
      Males
      (grams/day)
      1 - 2 18-19 18-19
      2 - 3 18-21 18-21
      4 - 6 26-28 26-28
      7 - 10 31-34 31-34
      11 - 14 51-55 50-54
      15 - 18 50-55 66-73

    The plant foods highest in protein are legumes (beans, peanuts, soyfoods such as tofu) and nuts, but grains and vegetables also contribute significant amounts.

      Protein Content of Common Vegan Foods
        Serving Protein (g)
      Naturade soy protein powder 1/3 Cup 23 g
      Naturade soy-free protein powder 1/3 Cup 22 g
      Seitan 3 oz 22.5
      Tofu 1/2 Cup 10 - 20
      Veggie dog/burger 1 6 - 18
      Tempeh* 3 oz 15.5
      Soybeans* 1/2 Cup 14.3
      Texturized soy protein 1/2 Cup 11
      Soymilk 1 Cup 5 - 10
      Lentils* 1/2 Cup 8.9
      Peanut butter 2 Tablespoons 8
      Chickpeas* 1/2 Cup 7.5
      Refried beans* 1/2 Cup 6.9
      Sunflower seeds 1/4 Cup 6.2
      Oatmeal* 1 Cup, instant 5.9
      Brown rice* 1 Cup 5
      Broccoli* 1 Cup chopped 4.6
      Potato, baked 1 medium 4.5
      Walnuts 1/2 oz (7 halves) 4.3
      White rice* 1 Cup 4.1
      Almonds 1/2 oz (12 kernels) 3
      Kale* 1 Cup chopped 2.5
      Taco shell 1 medium 1
      Carrot 1 med 0.6
      *Cooked

    Click here to check the USDA National Nutrient Database for the content of protein or other nutrients in foods.

    Vegans Might not Meet Protein Needs If...

    Vegans might not meet their protein needs, resulting in a loss of muscle mass and/or reduced immunity, if:

    • Food intake does not meet energy needs such as in cases of anorexia nervosa, depression, poverty, lack of appetite due to illness,3 or dieting.
    • Higher-protein plant foods are not included in sufficient amounts. This can happen when:
      • Most food eaten is junk food such as French fries, soda, etc.
      • Protein is believed to be unimportant and/or higher protein foods are avoided (such as in some fruitarian or raw food diets).
      • Legumes are avoided.3 (Other high-protein foods should be used.)

    Vegan athletes interested in how much protein they need should see:

    For more information on the amino acid DRIs and content of plant foods, see Where Do You Get Your Protein?

    Non-Protein Amino Acids

    Taurine and Carnitine

    Taurine and carnitine are non-essential amino acids found primarily in animal products. If you are eating enough protein, your body should make what you need. If you go an extended period of time without eating enough protein, or if you have a metabolic problem, you might benefit from a period of supplementation. In such cases, it is prudent to contact a health professional. There is no reason for most vegetarians or vegans to be concerned.

    Non-vegetarians typically eat 40 - 70 mg of taurine per day41 and 100 - 300 mg of carnitine per day.42 Country Life's Vegetarian Support multi-vitamin contains 25 mg of taurine per tablet.

    A carnitine metabolic problem has been linked to migraines. If you are a vegan who started getting migraines after becoming vegan, you might consider talking to your health professional about carnitine supplementation.

    Creatine

    Creatine is a combination of the amino acids glycine, arginine, and parts of methionine. It is used in skeletal muscle for quick energy. The body can make its own creatine. It is in animal flesh, but not plant foods.

    Because vegetarians do not eat any creatine (the average intake for a meat-eater is 2 g/day11), it is thought that vegetarian athletes might benefit from supplementation. Manufacturers claim that creatine supplements are synthesized from non-animal products.11 Before taking creatine, vegetarian athletes should read up on the subject such as in the article by Larson11 and the section on creatine in Becoming Vegan3.

    Iron

    Iron-deficiency anemia is probably one of the most inaccurately self-diagnosed illnesses. Only a medical doctor can diagnose it properly and people who think they may be suffering from it should see a doctor.

    Iron-deficiency symptoms include pale skin, brittle fingernails, fatigue, weakness, difficulty breathing upon exertion, inadequate temperature regulation, loss of appetite, and apathy.

    Iron in vegetarian diets is a somewhat controversial topic for a number of reasons.

    Iron is prevalent in many plant foods.

      Iron Content of Common Foods
        Serving mg
      fortified cereals 1/2 C varies
      soybeansA 1/2 C 4.4
      blackstrap molasses 1 T 3.3
      pumpkin seeds 2 T 2.5
      chickpeasA 1/2 C 2.4
      pinto beansA 1/2 C 2.2
      apricots, dried 1/4 C 1.5
      spinachA 1/2 C 1.5
      raisins 1/4 C 1.1
      A - Cooked; T - tablespoon

    But, while vegans normally have as high, or higher, iron intakes as non-vegetarians, plant iron is normally not absorbed as well as iron from meat.

    Because of this lower absorption, vegetarians' ferritin (the storage form of iron) levels are often lower than non-vegetarians. Even with the lower amounts of stored iron, cross-sectional studies to date have not shown higher rates of iron-deficiency anemia among vegetarians. But despite the fact that no differences in anemia have been found, it does not rule out the possibility that there are people (especially menstruating women) who stop being vegetarian after feeling the effects of lower iron absorption.

    I have met many ex-vegetarian women (and a few men) who claimed to become anemic after becoming vegetarian. In most cases, they did not have a doctor diagnose them. Rather, they just assumed they were anemic because they were tired. This could be due to numerous things, such as not eating enough calories, protein, or eating too many high-sugar, refined foods. But, I have heard it enough that I do think there is a possibility that some women have a hard time with the lower iron absorptoin of plant foods, especially when first becoming vegetarian.

    I say that iron absorption may be more of a problem when people first become vegetarian because long-term studies of vegetarian women have not shown high drop out rates. Physiologically, it makes some sense that the problem would tend to show up right away or not at all, for the following reason.

    The body secretes a transport protein, transferrin, into the digestive tract when iron stores are low. This protein helps shuttle iron from the food you eat into the bloodstream. If someone has been a meat-eater all her life, her body has not had a need to manufacture as much transferrin as she might need as a vegetarian. This might cause a quick drop in iron absorption once she becomes a vegetarian. Someone's body may or may not become more efficient at producing transferrin over time, but if she becomes anemic right away she will likely quit the diet and not give her body the chance.

    Of course, there are ways around this. Vitamin C significantly aids in iron absorption (the iron and vitamin C must be eaten at the same meal). In one study, vegetarian children with iron deficiency anemia in India, were given 100 mg of vitamin C at both lunch and dinner for 60 days. They saw a drastic improvement in their anemia with most making a full recovery.39 And, of course, there are iron supplements.

    Calcium supplements, coffee, and tea inhibit iron absorption if eaten at the same time as iron, so avoid them at meals in which you are trying to increase iron absorption.23

    For more information, see What should I do if my doctor tells me to eat meat because I have iron deficiency anemia?

    On a personal note, a few years ago I was feeling more tired than normal during workouts. I thought maybe I was suffering from anemia, so I had it checked. I was fine. I decided to eat more food, put on a few pounds, and my level of energy returned and I have felt energetic ever since.

    Anemia is a possible downside to lower iron absorptions, but there are a few potential upsides:

      1. Low iron stores are associated with higher glucose tolerance and therefore could prevent diabetes.
      2. High iron stores have been linked to heart disease. Based on an early study, this was believed to be a strong link for a number of years. Now that more evidence has come in, the link appears to be only in cases of very high iron storage levels, such as greater than 200 mcg/l (vegans' ferritin levels are rarely above 100 mcg/l). For now, the Food and Nutrition Board of the Institute of Medicine says, "This body of evidence does not provide convincing support for a causal relationship between the level of dietary iron intake and the risk for CHD [coronary heart disease]."32
      3. High iron stores have been linked to cancer. The association with cancer appears stronger than for heart disease.

    Hemochromatosis is a disease of increased iron absorption. Its most serious, homozygous form occurs in about 1 in 100 blacks and 1 in 200 nonblacks. Its less serious, heterozygous form occurs in 30% of blacks and 12% of nonblacks.33 Most affected people do not know they have the disease.33 People with hemochromatosis are at risk for cirrhosis,33 liver cancer,32 and other diseases. Alcoholic cirrhosis, other liver diseases, iron-loading abnormalities, and other rare diseases can also cause iron overload.32

    The Upper Limit for iron is set to prevent gastrointestinal distress and not to prevent possible chronic diseases from iron overload.32

    Amounts listed on a nutrition label are based on 18 mg/day.
    For example, 25% of the Daily Value = .25 * 18 mg = 4.5 mg.

    The new U.S. DRIs for iron distinguished between vegetarians and nonvegetarians. The DRI for vegetarians was determined by increasing the regular DRI by 1.8 times.21 However, this is very controversial because the recommendations were not based on studies of vegetarians. Most vegetarian dietitians do not think it is necessary to get this much iron. For that reason, the DRI's for non-vegetarians are listed here.

      Dietary Reference Intake (DRI) for Iron
      Age
      (years)
      DRI
      (mg)
      Upper limitA
      (mg)
      .5 - 1 11 40
      1 - 3 7 40
      4 - 8 10 40
      9 - 13 8 40
      boys, 14-18 11 45
      girls, 14-18 15 45
      breastfeeding females, 14-18 10 45
      men 19+ 8 45
      women 19-50 18 45
      breastfeeding women 19-50 9 45
      women 50+ 8 45
      pregnancy 27 45
      A - Do not exceed the upper limit.
      Those who engage in regular, intense exercise may need an additional 30%.21

    Recommendations for Iron

    You do not need to worry about iron if you are otherwise healthy and eat a varied vegetarian or vegan diet. If you suspect an iron deficiency, see a doctor. If your doctor thinks your iron stores are too low, eating meat (which is unnecessary) or taking an iron supplement may be suggested. Taking a 100 mg vitamin C tablet with two meals a day for 60 days, and refraining from tea and coffee during meals, should improve the anemia. If not, consult a doctor about iron supplementation.

    Zinc

    Zinc is not found in large amounts in plant foods, but vegetarians tend to have adequate zinc status. Zinc is found in legumes, nuts, corn, peas, cashews, peanuts, peanut butter, pumpkin seeds, and sunflower seeds; cereals are often fortified with zinc.

    Symptoms of zinc deficiency include poor growth and delayed sexual maturation in children, poor wound healing, hair loss, impaired immune function, and dermatitis (especially around body orifices).23

    Protein increases zinc absorption. Because of this, foods high in protein and zinc, such as legumes and nuts, are good choices.26 The leavening of bread (most bread is leavened) and fermenting of soyfoods (tempeh and miso) also enhances zinc absorption.26

    Selenium

    Selenium intake is more related to the selenium content of the soil than to dietary pattern. U.S. and Canadian soil appears to be adequate in selenium. Studies of vegetarians and vegans in the U.S. have shown them to have adequate intakes. Selenium is found in many foods, but in higher amounts in Brazil nuts, whole grains (whole-wheat bread, oatmeal, barley), white rice, and beans.22

    Vitamin A

    Pre-formed vitamin A exists only in animal products. However, there are about 50 carotenoids that the body can convert into vitamin A; the most common is beta-carotene. The vitamin A content of foods is now stated as retinol activity equivalents (RAE). The DRI of 900 RAE for men and 700 RAE for women, can be met with:

    Food Amount RAE
    Carrot 1 Medium 1012
    Baked Sweet Potato 1 Medium 1244
    Cantaloupe 2/3 1290
    RAE - Retinal activity equivalents

    Other sources include kale, mango, spinach, butternut squash, and various greens.

    Other Nutrients & Multivitamins

    Some people may have specific problems absorbing or utilizing certain nutrients (regardless of their diet). Some nutrients are normally provided adequately by a varied vegan diet, but can be low in some vegans' diets. Riboflavin (vitamin B2) and pyridoxine (vitamin B6) are two examples. While most vegans have no problem with vitamin B6, numerous members of one vegan family showed symptoms of vitamin B6 deficiency.24

    Symptoms of vitamin B2 deficiency are sores outside of the lips and in the corners of the mouth, swollen tongue and mouth cavity, and dermatitis.23 Vitamin B2 is found in a wide variety of plant foods in small amounts, including avocados, mushrooms, almonds, leafy green vegetables, and soybeans.26

    Symptoms of B6 deficiency include sleepiness, fatigue, sores in the sides of the mouth, and a swollen tongue.23 Bananas, navy beans, and walnuts are all good sources of vitamin B6.23

    Cereals fortified with iron, zinc, and B vitamins can add some ensurance of getting adequate amounts.

    Some researchers suggest taking a modest multivitamin supplement regardless of your diet. I recommend one that is about 25-100% of the DRIs. B vitamins can be taken in higher amounts. Tablets can be broken in half.

    Pregnancy
    Click here (opens in new window) to read the article, Vegan Pregnancy, by Reed Mangels, PhD, RD. from the Jan/Feb 1997 issue of The Vegetarian Journal.
    Infants

    The American Dietetic Association and the American Academy of Pediatrics agree that well-planned vegan diets can satisfy the nutrient needs and normal growth of infants.25

    Breast-feeding is the best option when possible. Vegan parents should not try to make their own infant formulas as this often leads to poor child development. Although more research is desirable, it appears that soy infant formulas are generally safe. See below for information regarding soy formulas.

    Breast milk is low in vitamin D and varies according to the mother's intake/sun exposure. According to some experts, dark-skinned, breast-fed babies should be given vitamin D supplements.18

    For more information see:

    Soy Formulas

    If you need to feed your baby formula, soy formulas are available. Unfortunately, they all contain vitamin D3 which usually comes from sheep's wool or fish. As of 2001, the following brands were vegan except for the vitamin D3:

    Click here for thoughts on the subject of trying to be 100% vegan.

    Are infant soy formulas safe?

    Infant soy formulas have been around for many years and used without apparent problems. However, there has recently been a concern that the isoflavones in soy could be harmful for infants.

    Click here for an abstract of the only long-term study comparing infants receiving cow's milk formula to infants receiving soy formula.

    Click here for an abstract of a more recent review of the subject.

    Click here for an article about a recent, ongoing study of soy infant formulas conducted by the Agricultural Research Service of the USDA. A summary of the article is that there have been no observed negative effects of soy formulas in humans but some animal research has raised concerns that soy formulas may cause infants to metabolize drugs abnormally fast. While this has not yet been directly studied in human infants, it seems that researchers looking at other aspects of soy formulas' effects on infants would have observed manifestations of abnormally fast drug metabolism if it were a common or serious problem.

    Children

    For more information, see:

    Fiber and Children

    The American Academy of Pediatrics recommends that children eat no more than .23 g of fiber per pound of body weight per day. Vegan children can easily exceed this limit. They might come closer to recommendations by eating half of their servings of grains as refined grains (e.g., white pasta, white rice, white bread).26

    Vegan children who do not eat much because they get full easily may benefit from eating some low-fiber foods such as refined grains, peeled fruits and vegetables, and added oils.26 Nuts and nut butters can also increase their calorie and protein intake. For younger children, be sure to chop or grind nuts well enough to prevent choking.

    Benefits of Selected Vegan Foods
    Beans and Nuts

    In addition to being excellent sources of protein, beans and nuts have many other benefits such as vitamins, minerals, fiber, and other chemicals that may prevent cancer and heart disease.28,29 Nuts also contain monounsaturated fats which are healthy for the heart. In one study, eating nuts (including peanuts34) 5 or more times per week reduced heart disease by about 50%!1

    Fruit and Vegetables

    High fruit and vegetable consumption has been associated with a reduced risk for cardiovascular disease, several common cancers, and other chronic diseases (such as macular degeneration and cataracts).

    Whole Grains

    Whole-grain consumption has been associated with a reduced risk for heart disease, diabetes, hypertension, and stomach and colon cancer. Whole grains include brown rice, whole-wheat bread, barley, oatmeal, corn, quinoa, and millet.

    Summary of Daily Suggestions for Vegan Adults
      Recommended Daily IntakesA
    Vitamin B12 3-100 mcg (g)
    Omega-3 fats 2.2 - 3.3 g; about 1 tsp of flaxseed oil or 1 Tbsp of ground flaxseeds
    Calcium 1000 - 1200 mg; (i.e., 3 servings of high-calcium foods or supplements)
    Vitamin D 5-15 mcg (200-600 IU)
    Iodine 75 - 150 mcg every few days
    General Health Plenty of green and yellow vegetables, other vegetables, fruits, nuts, legumes, and whole grains
    A - See individual sections for needs of other age groups.
    Vegan Multivitamins

    Companies often change the amount of vitamins and minerals in their multivitamin supplements. The information below was as of the last time I checked.

    Click here for thoughts on the subject of trying to be 100% vegan.

      B12
    mcgA
    Iodine
    mcg
    D2
    mcg (IU)
    per bottle Approx.
    Cost
    Country Life in health food stores
    Vegetarian Support
    125 none 2.5 (100) 60 T $12
    Deva Nutrition Vegan Multivitamin
    Available from: Bodybuilding.com and VegetarianVitamin.com
    50 150 10 (400) 90 T $13
    Deva Nutrition iron-free vegan multivitamin 100 150 10 (400) 90 T $13
    Freeda
    Freedavite Tiny Tablet Multi-Vitamin & MineralB
    6 75 10 (400) 250 T $13
    Pangea 800-340-1200
    VeganLife Multivitamin
    100 50 3.3 (133) 90 T $13
    Prescription2000 916-483-1085
    Daily Multivitamin/Mineral
    75 38 2.5 (100) 120 C $18

    VegLife in health food stores
    Vegan One Multiple

    100 150 10 (400) 60t $13
    A - microgram = mcg = g
    B - Company says their vitamin A (palmitate) and D are from non-animal sources.
    C - Numbers are calculated per tablet (T) or capsule (C).

    Other vegan multivitamins:

    Futurebiotics Vegetarian Super Multi futurebiotics.com
    KAL Vegetarian Multiple 1-800-733-4525
    Nature's Life vegetarian Mega-Vita-Min iron free natlife.com
    Freeda Ultra, iron-free
    Freeda Quintabs-m, iron-free
    Ultra Freeda, A-Free (w/Iron)
    freedavitamins.com
    Footnotes

    1. Fraser GE. Associations between diet and cancer, ischemic heart disease, and all-cause mortality in non-Hispanic white California Seventh-day Adventists. Am J Clin Nutr. 1999 Sep;70(3 Suppl):532S-538S.

    2. Key TJ, Fraser GE, Thorogood M, Appleby PN, Beral V, Reeves G, Burr ML, Chang-Claude J, Frentzel-Beyme R, Kuzma JW, Mann J, McPherson K. Mortality in vegetarians and nonvegetarians: detailed findings from a collaborative analysis of 5 prospective studies. Am J Clin Nutr. 1999 Sep;70(3 Suppl):516S-524S.

    3. Davis B, Melina V. Becoming Vegan: Summertown, TN: Book Publishing Co; 2000.

    4. Outila TA, Lamberg-Allardt CJ. Ergocalciferol supplementation may positively affect lumbar spine bone mineral density of vegans. J Am Diet Assoc 2000 Jun;100(6):629.

    5. Barr SI, Prior JC, Janelle KC, Lentle BC. Spinal bone mineral density in premenopausal vegetarian and nonvegetarian women: cross-sectional and prospective comparisons. J Am Diet Assoc 1998 Jul;98(7):760-5.

    6. Hu JF, Zhao XH, Jia JB, Parpia B, Campbell TC. Dietary calcium and bone density among middle-aged and elderly women in China. Am J Clin Nutr 1993 Aug;58(2):219-27.

    7. Janelle KC, Barr SI. Nutrient intakes and eating behavior scores of vegetarian and nonvegetarian women. J Am Diet Assoc 1995 Feb;95(2):180-6, 189, quiz 187-8.

    8. Lau EM, Kwok T, Woo J, Ho SC. Bone mineral density in Chinese elderly female vegetarians, vegans, lacto-vegetarians and omnivores. Eur J Clin Nutr 1998 Jan;52(1):60-4.

    9. Parsons TJ, van Dusseldorp M, van der Vliet M, van de Werken K, Schaafsma G, van Staveren WA. Reduced bone mass in Dutch adolescents fed a macrobiotic diet in early life. J Bone Miner Res 1997 Sep;12(9):1486-94.

    10. Wardlaw GM. Perspectives in Nutrition, 4(th) Ed. Boston, MA: McGraw-Hill; 1999.

    11. Vegetarian Diet for Exercise and Athletic Training and Performing: An Update, by D. Enette Larson, MS, RD, LD.

    12. Key TJ, Davey GK, Appleby PN. Health benefits of a vegetarian diet. Proc Nutr Soc. 1999 May;58(2):271-5.

    15. Mezzano D, Munoz X, Martinez C, Cuevas A, Panes O, Aranda E, Guasch V, Strobel P, Munoz B, Rodriguez S, Pereira J, Leighton F. Vegetarians and cardiovascular risk factors: hemostasis, inflammatory markers and plasma homocysteine. Thromb Haemost 1999 Jun;81(6):913-7

    18. Vitamin D. Vegetarian Nutrition & Health Letter Loma Linda University School of Public Health. 2001;4(5):1-5.

    19. Appleby PN, Thorogood M, Mann JI, Key TJ. The Oxford vegetarian study: an overview. Am J Clin Nutr 1999 Sep;70(3 Suppl):525S-531S.

    20. Lightowler HJ, Davies GJ. Iodine intake and iodine deficiency in vegans as assessed by the duplicate-portion technique and urinary iodine excretion. Br J Nutr 1998 Dec;80(6):529-35I.

    21. Mangels R. "Update on the New DRI's" Vegetarian Nutrition Update Sum 2001;10(4):1-7.

    22. Messina M, Messina V. The Dietitian's Guide to Vegetarian Diets. Gaithersburg, MD: Aspen Publishers, Inc., 1996.

    23. Groff J, Gropper S. Advanced Nutrition and Human Metabolism, 3rd ed. Wadsworth: 2000.

    24. Crane MG, Register UD, Lukens RH, Gregory R. "Cobalamin (CBL) studies on two total vegetarian (vegan) families" Vegetarian Nutrition 1998; 2(3):87-92.

    25. Mangels AR, Messina V. Considerations in planning vegan diets: infants. J Am Diet Assoc. 2001 Jun;101(6):670-7.

    26. Messina V, Mangels AR. Considerations in planning vegan diets: children. J Am Diet Assoc. 2001 Jun;101(6):661-9.

    27. Fraser GE, Shavlik DJ. Ten years of life: Is it a matter of choice? Arch Intern Med. 2001 Jul 9;161(13):1645-52.

    28. Messina MJ. Legumes and soybeans: overview of their nutritional profiles and health effects. Am J Clin Nutr. 1999 Sep;70(3 Suppl):439S-450S.

    29. Kris-Etherton PM, Yu-Poth S, Sabate J, Ratcliffe HE, Zhao G, Etherton TD. Nuts and their bioactive constituents: effects on serum lipids and other factors that affect disease risk. Am J Clin Nutr. 1999 Sep;70(3 Suppl):504S-511S.

    30. American Dietetic Association; Dietitians of Canada. Position of the American Dietetic Association and Dietitians of Canada: Vegetarian diets. J Am Diet Assoc. 2003 Jun;103(6):748-65.

    32. Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc. Washington, DC: National Academy Press, 2001.

    33. Mahan LK, Escott-Stump S. Krause's Food, Nutrition, & Diet Therapy, 10th ed. Philadelphia, PA: W.B. Saunders, Co., 2000.

    34. Personal communication with Gary Fraser of the Adventist Health Study. October 22, 2001.

    36. Conquer JA, Holub BJ. Supplementation with an algae source of docosahexaenoic acid increases (n-3) fatty acid status and alters selected risk factors for heart disease in vegetarian subjects. J Nutr. 1996 Dec;126(12):3032-9.

    37. Artemis P. Simopoulos, MD, Alexander Leaf, MD, Norman Salem, Jr, PhD. Workshop on the Essentiality of and Recommended Dietary Intakes for Omega-6 and Omega-3 Fatty Acids. National Institutes of Health (NIH) in Bethesda, Maryland, USA, April 7-9, 1999.

    38. Roshanai F, Sanders TA. Assessment of fatty acid intakes in vegans and omnivores. Hum Nutr Appl Nutr. 1984 Oct;38(5):345-54.

    39. Seshadri S, Shah A, Bhade S. Haematologic response of anaemic preschool children to ascorbic acid supplementation. Hum Nutr Appl Nutr. 1985 Apr;39(2):151-4.

    41. Rana SK, Sanders TA. Taurine concentrations in the diet, plasma, urine and breast milk of vegans compared with omnivores. Br J Nutr. 1986 Jul;56(1):17-27.

    42. Siebrecht S. L-Carnitine: physiological and pharmacological effects! Ann Nutr Metab 2000;44:79.