Nutritional Determinants of Homocysteinemia

Overview

Background.
Vitamin B12, folate and vitamin B6 are the main determinants of homocysteinemia. These B-groupvitamins influence two metabolic pathways of homocysteine reduction, which prevail in dependence to methionineintake. Transsulfuration (vitamin B6) dominates under condition of overnutrition with prevalence of animal foodsources, remethylation (vitamin B12 and folic acid) is decisive under conditions of malnutrition, alternative nutritionor optimal traditional diet.Methods and Results. Plasma homocysteine and folic acid, vitamins B12 and B6 in serum were measured inalternative nutrition groups of adults (vegans, vegetarians (lacto+lactoovo), semivegetarians, n=39) and comparedwith those values in group consuming traditional diet – control group, general population (n=35). In alternativenutrition groups, the average homocysteine level is significantly higher (vegans 17.2 µmol/l, vegetarians 12.9 µmol/l,semivegetarians 10.1 µmol/l, control group 9.9 µmol/l); the frequency of hyperhomocysteinemia (over 15 µmol/l)is 50 %, 32 %, 14 % vs. 6 % in control group. Vegetarians and vegans have a significantly higher levels of vitaminB6 and folic acid; the frequency of vitamin B6 deficit is 60 % and 57 % in control group and semivegetarian groupvs. 16 % and 0 % in vegetarian and vegan group. Folate deficit was found in 16 % of traditional group vs. 0 % inalternative groups. Serum levels of vitamin B12 are significantly reduced in subjects consuming alternative nutritionwith deficiency observed in 67 % of vegans, 32 % of vegetarians, 14 % of semivegetarians vs. 0 % in control group.Conclusions. Vitamin levels in relation to nutritional regime and metabolic pathways of homocysteine show thatthe mild hyperhomocysteinemia in alternative nutrition is a consequence of vitamin B12 deficiency. In traditionallyfed population, higher plasma homocysteine values is caused by folate deficiency. These conclusions are supportedby a significantly negative linear correlation of homocysteine – folic acid levels (traditional nutrition) and homocysteine– vitamin B12 levels (alternative nutrition). In case of vitamin B6, a similar correlation was not found.

Key words:
homocysteine, folic acid, vitamin B12, vitamin B6, alternative nutrition, traditional nutrition.