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Vegan Health Study by Michael Klaper, M.D.​​

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Vegan Health Study

by Michael Klaper, M.D.

Update: January 4, 2017


I have practiced medicine for 40+ years and served as the Director of the non-profit Institute of Nutrition Education and Research from 1992 through 2015. For the past 30+ years, I've helped people to transition to a completely plant-based (vegan) diet.


The Study

From 2002 - 2007, the Institute conducted a study focusing on people who ate a completely plant-based (vegan) diet and, particularly, those who felt they were failing to thrive (often underweight and/or reporting low energy levels).

1,208 people answered our online survey about their eating habits and lifestyle activities. 45 of those participants underwent a battery of blood tests through Metametrix Laboratories (which has since merged with Genova Diagnostics) measuring organ function and nutrient levels, including essential fatty acids, nutrient-related minerals, and amino acid profiles.



My conclusions support what I've encountered in my years of medical practice. Many vegans who fail to thrive show low levels of two essential fats, three essential minerals, one or more branched-chain amino acids, and a key antioxidant; many also have elevated levels of pro-inflammatory omega-6 fatty acids, as described below.


The omega-3 fatty acids, (a) DHA (docosahexaenoic acid - 28/45 subjects showed deficiencies) and (b) EPA (eicosapentaenoic acid - 18/45 showed deficiencies). Both are required for brain and nerve function, skin oils, etc.



a. Zinc is an earth element needed to maintain the health of one's immune system and skin, and for carbohydrate metabolism. (13/45 showed deficiencies.)

See a study describing the nutritional status of zinc and selenium in vegetarianspublished in 2009 by Biological Trace Element Research.


b. Magnesium, used in over 300 chemical reactions in the body, is essential for nerve and muscle function, and for keeping the immune system and bones strong. (19/45 showed deficiencies.)


 c. Chromium is required for metabolism of carbohydrates and fats. (11/45 showed deficiencies.)

Other mineral deficiencies included: manganese (8/45) and molybdenum (7/45). These are further validations of the importance of eating a wide variety of vegetables, whole grains, legumes, seeds, nuts, and fruits that contain these minerals.

Note: According to Dr. Michael Greger, vegan diets tend to be deficient in three nutrients (calciumiodine, and vitamin B12), whereas average omnivores tend to be deficient in seven nutrients. See his short video (85-seconds) below:

Dr. Michael Greger is a physician, New York Times bestselling author, and internationally recognized speaker on nutrition, food safety, and public health issues. See his website for more information.




CoQ-10 is a key antioxidant substance essential for immune health and energy production. Sources include broccoli, spinach, soybeans, and cauliflower. (19/45 showed deficiencies.)




Branched-chain amino acids (valine, leucine, isoleucine) are essential for muscle function and growth. Sources include soybeans, baked beans, lima beans, lentils, brown rice, whole wheat, corn, and nuts. (22/45 subjects showed deficiencies.)




Elevated levels of omega-6 fatty acids are associated with inflammatory reactions throughout the body and largely ingested through vegetable oils in processed foods. (7/45 showed excessive amounts.)

Conclusions & Recommendations

I concluded from the study that people who consume a vegan diet need to not only recognize the importance of plant-based diets, but to actually EAT THE PLANTS!

“Junk food vegans” who mostly consume devitalized, processed foods, laden with salt, sugar, and oils (SOS) are the ones who are most likely to fail to thrive. (See my 73-minute On Demand Video and DVD, “Salt, Sugar and Oil: What You Need To Know.”)


1. Emphasize WHOLE PLANT FOODS in your diet - large, colorful salads, several pieces of fruit each day, generous portions of steamed green and yellow/orange vegetables, whole grains, vegetable-rich soups, stews, at least one cup of legumes daily (beans, peas, chickpeas), and nuts and seeds containing the nutrients listed above - as opposed to processed foods (in packages, boxes, and most restaurant meals) and supplements.

Note: As and when available, I choose locally grown food that's certified organic.

2. Eat magnesium-rich foods daily, including LARGE helpings of dark, leafy greens, such as kale, broccoli, spinach, chard, etc., and whole grains, especially oats, raw almonds and cashews (small handfuls chewed to a cream), bananas, sweet potatoes, winter squash, wild and brown rice, and a cup of legumes (beans, peas, chickpeas, lentils, etc.) in stews, soups, hummus spreads, no-cheese burritos, etc.

3. Ensure reliable sources of zinc - another reason to include generous helpings of at least one cup of whole grains and beans and the other whole plant foods listed above, since they all have some zinc. For “nutritional insurance,” one can take an approved zinc-containing supplement, such as Dr. Joel Fuhrman’s multivitamin and mineral supplements (see below). (Note: I am not compensated by Dr. Fuhrman for recommending his products.)

I recommend an excellent article on zinc by registered dietician Jack Norris, R.D., based in part, on data in the USDA Food Composition Database.

4. Ensure adequate sources of chromium with frequent consumption of these whole plant foods: whole grains, especially, brown rice and barley (if not gluten intolerant), greens such as broccoli and green beans, mushrooms, nutritional yeast, (non-GMO) corn, potatoes, and Brazil nuts (limit 2/week due to selenium content).


5. Although our study did not test for iodine, a mineral necessary for normal thyroid function, I have since come to suspect that iodine deficiency, resulting in low thyroid function, may be playing a role in some vegans who are “failing to thrive.” Consequently, I now recommend all vegans ensure an adequate iodine source by including sea vegetables in soups and salads, as described by Dr. Michael Greger in this short video, “Avoiding Iodine Deficiency” (click the image below to begin play):

If you’re concerned about the California Warning on Sea Vegetables (Prop 65) and testing and purity of Maine Coast Sea Vegetables, including heavy metals, use the two links in this sentence.

Dr. Joel Fuhrman’s daily multivitamins (see below) have a reasonable 15 mg. of zinc and 150 mcg of iodine.

6. Ensure adequate daily intake of omega-3 fatty acids DHA and EPA with a small handful of walnuts daily, and 1-2 tablespoons of ground flaxseeds, hemp seeds, or chia seeds on salads and cereals. On most days, 150 - 300 mg. of supplemental, algae-derived DHA and EPA is advisable (available online or in natural food stores).


7. Omega-6 fatty acids are associated with inflammation of many tissues in the human body and largely ingested through vegetable oils in processed foods. Avoid inflammation-inciting omega-6 oils by reducing - or eliminating - processed foods, especially food fried in, or containing, oils (e.g., chips, baked goods, candies, etc.).


8. Recommended Supplements

Dr. Joel Fuhrman is a board-certified physician with over 25 years experience in nutritional medicine, president of the Nutritional Research Foundation, and author of bestselling books. (Several of Dr. Fuhrman’s books are included in recommendations on my website at

In re-formulating his vitamin products, Dr. Fuhrman removed the most problematic substances in common standard multivitamins – vitamin A, beta carotene, folic acid, iron, etc. He appropriately reduced the amounts of thiamin and riboflavin to very modest levels, provided an “insurance” dose of 2,000 IU of vitamin D, and included reasonable quantities of the nutrients that can be the most challenging for vegans to obtain, namely vitamin B12, zinc, and iodine.


It is because of this thoughtful and more physiologic formulation of nutrients that I recommend Dr. Fuhrman’s supplements – and, yes, I take them myself. (As noted above, I am not compensated by Dr. Fuhrman for recommending his products.)


Dr. Fuhrman’s DHA+EPA Purity, a liquid concentrate, is a vegan source of long-chain omega-3 fatty acids derived from lab-grown algae. His Women’s Daily Formulaincludes maitake mushroom blend extract (beta-glucan) known for its ability to support immune defenses. His Men’s Daily Formula includes pumpkin seed extract, saw palmetto, and tomato extract to support prostate health. Both include a formulation similar to Dr. Fuhrman’s Gentle Care Formula, a multivitamin and mineral supplement designed to aid digestion.

“Thriving on a Whole Food, Plant-Based Diet”

To learn what is required to truly thrive on a whole food, plant-based diet, I recommend viewing my 99-minute On Demand Video, “Thriving on a Plant-Based Diet.” It’s filled with valuable information and useful for all learning levels!

Click the image below to see my 2-minute introduction to the video:

Note: Rental enables unlimited streaming for 3-days (72 hours); purchase enables unlimited streaming indefinitely, plus the ability to download for off-line viewing.


I also invite you to browse my website - - to find a bounty of nutrition information, including my “Health Supporting Eating Plan” and dozens of other articles and videos about healthy eating and healthy living.


To keep informed, please sign-up to my free mailing lists to receive my Medicine Capsule newsletter and to be advised of my speaking appearances and nutrition-related events. E-mail and social media links appear at the bottom of this page.


Thanks for your interest in our vegan health study. Although it was conducted 20+ years ago, many people are still inquiring about it and its results are still important.


Yours in health,

- Michael Klaper, M.D.


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