This is a continuation of the series of posts regarding concerns of vitamin deficiency raised in the article posted on the Weston A. Price Foundation’s web page titled “Vegetarianism and Nutrient Deficiencies” by Christopher Masterjohn.
In the first article I wrote about how vegetarians or vegans who eat a varied plant-based diet are not at risk for deficiencies in fat soluble vitamins A, D, and K. Today I am going to talk about Vitamin B deficiencies.
Vitamin B12:
Vegans are indeed at risk for B12 deficiency. In the past, most people lived in close contact with their farm animals and consumed B12 left as residues by bacteria living on their un-sanitized vegetable foods. Because this is no longer the case, those eating a plant-based diet are now at risk for B12 deficiency. Vitamin B12 is found in animal foods, but it is not synthesized by plants or animals. Bacteria make biologically active vitamin B12, and animal tissues store it and pass it to other animals eating those animals tissues. Ruminants, like cows or goats, have bacteria in their stomachs that synthesize vitamin B12, which is then passed down and absorbed by their small intestines. Other carnivores get their B12 from eating these grazers.
Most cases of vitamin B12 deficiency seen in patients are due to diseases of the intestine. Damage to the stomach’s parietal cells, from disease or surgery, and damage to the intestine prevents absorption or reabsorption, causing the loss of B12. “Pernicious anemia” from B12 deficiency occurs once the body’s stores of vitamin B12 are depleted. It can take up to 3 to 6 years for it to manifest (when the body’s stores of vitamin B12 become depleted).(1)
Master john states that ” even vegetarians who supplement with standard B12supplements could be at risk for deficiency. ” This is simply untrue. Blood levels of B12 can be measured directly in the blood. I have been taking vitamin B12 supplements since I have been eating a plant-based diet for greater than 20 years and just had my B12 levels checked and they were high due to my supplementation. As long as vegans take an over the counter supplement of B12, there should be no problem with deficiency. Requirements are pretty minimal and easy to get with supplementation. I have a chart from the National Institutes of Health showing the different recommended amounts of B12 for different ages of people here: (2)
| Life Stage | Recommended Amount |
|---|---|
| Birth to 6 months | 0.4 mcg |
| Infants 7–12 months | 0.5 mcg |
| Children 1–3 years | 0.9 mcg |
| Children 4–8 years | 1.2 mcg |
| Children 9–13 years | 1.8 mcg |
| Teens 14–18 years | 2.4 mcg |
| Adults | 2.4 mcg |
| Pregnant teens and women | 2.6 mcg |
| Breastfeeding teens and women | 2.8 mcg |
Vitamin B6:
In the article, Masterjohn asserts that plant foods simply contain much less B6 than most animal foods and that the plant form of vitamin B6 is inferior to the animal food form because its conversion to the active form depends on B2 status, and vitamin B2 levels tend to be higher in animal foods. He states that plant foods contain much of their B6 bound up with sugars that make it difficult or impossible to absorb. He claims that plant foods require more cooking than animal products, decreasing the yield of active B6 in vegetarian diets, since heat destroys B6. He cites a study comparing lactating Nepalese women to their American omnivore counterparts The Nepalese women consumed more B6 but had lower serum levels of the active form. They had equivalent levels in their breast milk, but their infants had lower levels of the active form. It would be more fair to compare American vegans to American omnivores as Nepalese vegetarian women probably have less access to fresh fruits and vegetables containing B12.
That being said this article certainly does not prove that vegetarians will develop B6 deficiency as there are plenty of vegetarian sources of B6 including: soy, bananas, watermelon, peanut butter, almonds, sweet potatoes, green peas, avocados, hemp seeds, spirulina, chia seeds, beans, rice bran, chickpeas, sunflower seeds, pineapple, plantains, hearts of palm, artichokes, water chesnuts, all squash and pumpkin, Brussels sprouts, green beans, pistachios, figs, yeast, garlic, sage, peppers, kale, collards!(3) In a study comparing Korean Buddhist vegetarians to non-vegetarians, the vegetarians actually had slightly higher B6 levels than the non-vegetarians. (4)
Zinc:
I am also going to address his concerns for zinc deficiency in this post. Masterjohn states “Although [zinc is] present in grains, legumes, fruits and vegetables, it is found in much lower amounts compared to animal foods and is much less bioavailable…While a well planned vegetarian diet may escape overt zinc deficiency, it would be virtually impossible to maintain a truly robust zinc status without the inclusion of animal foods.”
An article by the American Dietetic Association addresses some of these concerns about zinc. The article states that the bioavailability of zinc in vegetarians may be lower than non-vegetarians, due to the higher phytic acid content of vegetarian diets, but zinc deficiency is not evident in Western vegetarians. Zinc sources include soy products, legumes, grains, cheese, and nuts. You can reduce the binding of zinc by physic acid by soaking and sprouting beans, grains, and seeds as well as leavening bread, increasing zinc bioavailability. Citric acid can also enhance zinc absorption to some extent. (5)
In conclusion, a person eating a well-balanced plant-based diet in western countries should not have difficulty in obtaining adequate amounts of B6 and Zinc. B12 will not be a problem with supplementation. Next week I am going to address the concerns about essential fatty acids, amino acids, and cholesterol raised in this article. Stay tuned!
(1) John McDougall. “Vitamin B12 deficiency-The Meat- Eaters’ Last Stand.” McDougall Newsletter. November 2007. Web. 07 September 2015. <https://www.drmcdougall.com/misc/2007nl/nov/b12.htm>
(2) “Vitamin B12 Factsheet for Consumers.” National Institutes of Health Office of Dietary Supplements. Web. 07 September 2015. <https://ods.od.nih.gov/factsheets/VitaminB12-Consumer/>
(3) Heather McClees. “B Vitamins: How to get them in a Vegan Diet.” One Green Planet. 11 July 2014. Web. 07 September 2015. <http://www.onegreenplanet.org/natural-health/b-vitamins-how-to-get-them-in-a-vegan-diet/>
(4) Lee, Yujin. “The nutritional status of vegetarian Buddhist nuns compared to omnivorous women in South Korea.” Web. 07 September 2015. <http://geb.uni-giessen.de/geb/volltexte/2011/8061/pdf/LeeYujin_2011_03_14.pdf>
(5) Craig WJ, Mangels AR. “Position of the American Dietetic Association.” Journal of the American Dietetic Association