Vitamin B12 Status Upon Short-Term Intervention with a Vegan Diet-A Randomized Controlled Trial in Healthy Participants.
Study Goal
The researchers aimed to determine the short-term effects of a vegan diet on vitamin B12 metabolism and status in healthy omnivores.
Results Summary
The vegan diet led to a significant reduction in serum vitamin B12 and holotranscobalamin (holo-TC) after four weeks, while MMA and tHcy levels remained unaffected. Cholesterol intake decreased, and nutrient profiles were adequate, but vitamin B12 intake was lower in the vegan group.
Population
53 healthy omnivore subjects
Effective Dosage
Not specified (unsupplemented vegan diet)
Duration
4 weeks
Interactions
None mentioned
| Intervention | Direction | Endpoint | Population | Dosage | Impact | Claim # |
|---|---|---|---|---|---|---|
controlled unsupplemented vegan diet | decrease | holotranscobalamin | healthy omnivore subjects | - | decreased significantly | #1 |
controlled unsupplemented vegan diet | no change | methylmalonic acid | healthy omnivore subjects | - | were unaffected | #2 |
controlled unsupplemented vegan diet | no change | total plasma homocysteine | healthy omnivore subjects | - | were unaffected | #3 |
controlled unsupplemented vegan diet | no change | body weight | healthy omnivore subjects | - | remained stable | #4 |
controlled unsupplemented vegan diet | decrease | cholesterol intake | healthy omnivore subjects | - | led to a significant reduction | #5 |
controlled unsupplemented vegan diet | decrease | vitamin B12 | healthy omnivore subjects | - | lower intake | #6 |
controlled unsupplemented vegan diet | decrease | serum vitamin B12 | healthy omnivore subjects | - | lower concentration | #7 |
controlled unsupplemented vegan diet | decrease | holotranscobalamin | healthy omnivore subjects | - | reduced | #8 |
Vegans are at an increased risk for certain micronutrient deficiencies, foremost of vitamin B12. Little is known about the short-term effects of dietary change to plant-based nutrition on vitamin B12 metabolism. Systemic biomarkers of vitamin B12 status, namely, serum vitamin B12 and holotranscobalamin, may respond quickly to a reduced intake of vitamin B12. To test this hypothesis, 53 healthy omnivore subjects were randomized to a controlled unsupplemented vegan diet (VD, n = 26) or meat-rich diet (MD, n = 27) for 4 weeks. Vitamin B12 status was examined by measurement of serum vitamin B12, holotranscobalamin (holo-TC), methylmalonic acid (MMA) and total plasma homocysteine (tHcy). Holo-TC decreased significantly in the VD compared to the MD group after four weeks of intervention, whereas metabolites MMA and tHcy were unaffected. Body weight remained stable in both groups. VD intervention led to a significant reduction of cholesterol intake, and adequate profiles of nutrient and micronutrient status. Lower intake of vitamin B12 was observed in VD, which was mirrored by a lower concentration of serum vitamin B12 and reduced holo-TC after 4 weeks. Plasma holo-TC may be a fast-responding biomarker to monitor adequate supply of vitamin B12 in plant-based individuals.