A plant-based diet does not put you at risk for deficiencies in fat-soluble vitamins.

Recently, a website from an organization that refers to themselves as the “Weston A. Price Foundation” has been brought to my attention.  This foundation was formed by Sally Fallon in 1999, far after Weston Price passed away in 1948.  They have called themselves a “nutrition education” foundation, but the unfortunate thing is that they advocate some unhealthy diet choices.

This blog post is a response to the concerns about fat soluble vitamin deficiency made in an article titled “Vegetarian and Nutrient Deficiencies” by Christopher Masterjohn on the their website stating that vegans are more likely to be deficient in fat-soluble vitamins.  There is no evidence for these claims.  The author states that he did not feel well on a vegan diet and suffered many maladies.  It is possible that he ate a diet that was not well-balanced and contained a lot of processed foods.  He talks about possible vitamin deficiencies that vegetarian or vegan people may encounter, under the premise that there is not enough fat in the diet for vegans to obtain adequate amounts of these fat soluble vitamins.  However, it has been shown that only a minimal amount of fat is needed to promote vitamin A absorption, 3-5 g . (1)

Vitamin A:

The author states that this fat-soluble vitamin is poorly absorbed on a vegan diet.  Vitamin A in its complete form, retinol, is only found in animal products; however, the precursors which are converted to vitamin A by our body, such as beta-carotene, are found the plants. (1)

The author cites a study of pregnant Indonesian women consuming enough carotenes but still suffering from marginal vitamin A deficiency.   These women were malnourished and not getting enough variation in their diet because they were poor.  There is little risk of vitamin A deficiency in vegetarians who regularly eat yellow-orange fruits and vegetables and leafy greens in developed countries.  In poor rural developing countries, fruits with beta carotene are often costly or seasonal.   In addition, children in the developing world may need more vitamin A since they may have reduced vitamin A absorption from diarrhea, increased utilization and excretion from diseases, such as measles or respiratory infections.(2)  Vitamin A deficiency happens rarely in modernized countries except in the elderly and malnourished.  There was a study done on Buddhist monks in Korea, and their Vitamin A levels were actually greater than those of the omnivores in the study. (3)

Vitamin D:

Vitamin D is  present in 2 forms: Ergocalciferol, or vitamin D2, (present in plants and some fish) and Cholecalciferol, or vitamin D3, made by the skin from sunlight.  People can get their vitamin D by ingesting it or being exposed to the sun for enough time to produce adequate amounts.  Vitamin D3 is made by the skin by way of ultraviolet UVB rays. UVB rays are present only during midday at higher latitudes and do not penetrate clouds. The time needed to produce adequate vitamin D from the skin depends on the strength of the UVB rays (latitude of residence), the time spent in the sun, and the amount of pigment in the skin. Tanning beds are not a reliable source of vitamin D.(4)

The major cause of vitamin D deficiency is the lack of sun exposure. Very few foods naturally contain vitamin D. Wild-caught salmon had on average 500–1000 IU vitamin D in 100 g (3.5 ounces), whereas farmed salmon contained much less (100–250 IU vitamin D per 100-g serving). Vitamin D is plentiful in the food chain but is not plentiful in the pelleted diet fed to farmed salmon.(5)

Vegetarians are not at risk for Vitamin D deficiency any more than their omnivorous associates.  A study was done on the Seventh Adventist population which includes vegetarians and non-vegetarians.  The researchers hypothesized that vegetarians would be more deficient in Vitamin D, but in the end found that they had similar Vitamin D levels to their omnivorous counterparts.(6)

Vitamin K2:

Vegans who eat leafy green vegetables are unlikely to be deficient in vitamin K.  Vitamin K2 is mainly found in animal products and fermented vegetables and cheeses.(7)  The author says that vegetarians are deficient in K2 since most people do not eat fermented vegetables. He cites the Rotterdam Study, which showed that K2 decreases heart disease.(8)  Other studies have been mixed, however.(9)  In the EPIC-Heidelberg study, vitamin K1 (from plants) was found to be inversely associated with a fatal heart attack, while K2 was associated with increased incidence of heart disease and increased fatal heart attack , though neither finding was statistically significant. (10)  It is possible that K2 reduces heart disease, but the jury is still not out.   I recommend eating fermented vegetables if you enjoy them.  However, if you do not, even if K2 carries some protective cardiac benefit, vegetarian and vegan individuals have been found to have overall reduced cardiovascular mortality over their meat-eating counterparts anyway.(11)

I am going to respond to the concerns about deficiencies in B vitamins and Zinc in my next post regarding this article.  Stay tuned!

(1) Racicot, Riccardo. “The age of information is also the age of misinformation- Claims regarding vegetarianism and vitamin A. ” The Vegetarian Resource Group Blog. The Vegetarian Resource Group. 28 August 2014. Web. 07 September 2015.<http://www.vrg.org/blog/2014/08/28/the-age-of-information-is-also-the-age-of-misinformation-claims-regarding-vegetarianism-and-vitamin-a/#sthash.OglmrGfw.dpuf>

(2) Sommer, Alfred MD, MHS.  “Vitamin A deficiency disorders, origins of the problem and approaches to its control.”  AgBioWorld.  Web. 07 September 2015.  <http://www.agbioworld.org/biotech-info/topics/goldenrice/vit_a.html>.

(3) 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>

(4) Kulie T, Groff A, Redmer J, Hounshell J, Schrager S. “Vitamin D: An Evidence-Based Review.”  J Am Board Fam Med 2009. 22 : 698-706

(5) Holick M, Chen T.  “Vitamin D Deficiency:  A Worldwide Problem with Health Consequences.”  The American Journal of Clinical Nutrition 2008. 87: 1080S-1086S.

(6) Chan J, Jaceldo-Siegl K, Fraser GE.  “Serum 25-Hydroxyvitamin D Status of Vegetarians, Partial Vegetarians, and non-vegetarians:  The Adventist Health Study-2.”  Am J Clin Nutr 2009;89(5):1686S-1692S.

(7) John Day MD.  “9 signs you may have vitamin k2 deficiency.”  Dr. John Day : Real Food. Real Living. Real Happiness.  Web.  07 September 2015. < http://drjohnday.com/9-signs-you-may-have-vitamin-k2-deficiency/>

(8) Geleijnse JM, Vermeer C, Grobbee DE, Schurgers LJ, Knapen MH, van der Meer IM, Hofman A, Witteman JC. Dietary intake of menaquinone is associated with a reduced risk of coronary heart disease: the Rotterdam Study. J Nutr. 2004;134(11):3100-5.

(9) Jack Norris.  “Vitamin K. ”  Veganhealth.org. Web.  07 September 2015.  <http://www.veganhealth.org/articles/vitamink#fn12>

(10) Nimptsch K, Rohrmann S, Linseisen J, Kaaks R. “Dietary intake of vitamin K and risk of incident and fatal myocardial infarction in the EPIC-Heidelberg cohort study” Gesundheitswesen 2010; 72: V143-DOI: 10.1055/s-0030-1266323.

(11) Le L, Sabate J.  “Beyond Meatless, the Health Effects of Vegan Diets:  Findings from the Adventist Cohorts.”  Nutrients. 2014; 6(6): 2131–2147.