Background. Vitamin B12, folate and vitamin B6 are the main determinants of homocysteinemia. These B-group
vitamins influence two metabolic pathways of homocysteine reduction, which prevail in dependence to methionine
intake. Transsulfuration (vitamin B6) dominates under condition of overnutrition with prevalence of animal food
sources, remethylation (vitamin B12 and folic acid) is decisive under conditions of malnutrition, alternative nutrition
or optimal traditional diet.
Methods and Results. Plasma homocysteine and folic acid, vitamins B12 and B6 in serum were measured in
alternative nutrition groups of adults (vegans, vegetarians (lacto+lactoovo), semivegetarians, n=39) and compared
with those values in group consuming traditional diet – control group, general population (n=35). In alternative
nutrition 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 vitamin
B6 and folic acid; the frequency of vitamin B6 deficit is 60 % and 57 % in control group and semivegetarian group
vs. 16 % and 0 % in vegetarian and vegan group. Folate deficit was found in 16 % of traditional group vs. 0 % in
alternative groups. Serum levels of vitamin B12 are significantly reduced in subjects consuming alternative nutrition
with 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 that
the mild hyperhomocysteinemia in alternative nutrition is a consequence of vitamin B12 deficiency. In traditionally
fed population, higher plasma homocysteine values is caused by folate deficiency. These conclusions are supported
by 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.
homocysteine, folic acid, vitamin B12, vitamin B6, alternative nutrition, traditional nutrition.