Vitamin B12 Supplementation Benefits Vegetarians

by | May 1, 2012 | 2012, Cardiovascular Health, Vegetarianism, Vitamin B12

Written by Greg Arnold, DC, CSCS.  Research shows vegetarians have a high rate of vitamin B12 deficiency, high salt intake and raised blood fat concentrations and that consuming vitamin B12 had a 9% improvement in blood flow. 

Despite claims that a vegetarian diet is heart-healthy, research has failed to prove this claim (1). Instead, research shows that vegetarians have a high rate of vitamin B-12 deficiency (70%), high salt intake and raised blood fat concentrations (2, 3), all of which increase their risk of atherosclerosis. As a result, finding ways to minimize heart disease risk factors in vegetarians is an issue requiring attention.

Now a new study (4) suggests that vitamin B12 supplementation may help heart health in vegetarians. In the study, 50 healthy subjects between 36 and 54 years of age who followed a vegetarian diet for at least 6 years were given either 500 micrograms of vitamin B12 per day or placebo for 12 weeks. The researchers measured blood vessel relaxation (called “ flow mediated dilation”) in the arm of each patient (5)) to assess any effects of B12 supplementation on blood vessel relaxation. Researchers also measured levels of an inflammatory protein called homocysteine.

Before the start of the study, 35 of the 50 vegetarians had vitamin B12 levels below 150 picomoles/Liter, classifying them as vitamin B12 deficient (6). While both groups had average starting B12 blood levels of 134.0 pmol/L, B12 supplementation significantly increased B12 blood levels (134.0 to 379.6 pmol/L – 183% increase) compared to placebo (134.0 to 185.7 pmol/L – 38% increase) in addition to significantly decreasing homocysteine levels (16.7 to 11.3 micromoles/Liter – 33% decrease) compared to placebo (16.7 to 13.1 micromoles/L – 22% decrease,p < 0.05).

When the researchers looked at flow-mediated dilation, those in the B12 group had a 9% improvement (6.3 to 6.9%) compared to no change in the placebo group (p <0.0001), showing B12 supplementation to increase blood levels, maintain a healthy level of inflammation, and help relax blood vessels.

For the researchers, “Vitamin B-12 supplementation improved arterial function in vegetarians with subnormal vitamin B-12 levels, proposing a novel strategy for atherosclerosis prevention.”

Source: Kwok, T., et al. “Vitamin B-12 supplementation improves arterial function in vegetarians with subnormal vitamin B-12 status.” The journal of nutrition, health & aging 16.6 (2012): 569-573.

© 2017 Springer International Publishing AG. Part of Springer Nature

Posted May 1, 2012.

References:

  1. Key TJ, Appleby PN, Davey GK, Allen NE, Specncer EA, Travis RC. Mortality in British vegetarians: review and preliminary results from EPIC-Oxford. Am J ClinNutr. 2003;78(suppl):533S-538S.
  2. Woo J, Kwok T,HoSC, Sham A, Lau E.Nutritional status of elderly Chinese vegetarians. Age Ageing 1998;27:455-461.
  3. Hung CJ, Huang PC,LuSC, Li YH, Huang HB, Lin BF, Chang, SJ, Chou HF. Plasma homocysteine levels in Taiwanese vegetarians are higher than those of omnivores. JNutr2002;132:152-158.
  4. Kwok T. Vitamin B12 Supplementation Improves arterial Function in Vegetarians with Subnormal Vitamin B12 Status. JouNutrHealth Aging 2012. DOI: 10.1007/s12603-012-0036-x.
  5. Kelme M.  Flow-mediated dilatation in human circulation: diagnostic and therapeutic aspects.  Jour Physiol – Heart 2002; 282 (1): H1-H5.
  6. “Vitamin B12” – posted on the National Institutes of Health-Office of Dietary Supplements website.