Iron, vitamin B12 and folic acid are key nutrients from the haematological aspect. Levels of the mentioned nutrients and haematological parameters were determined in a group of subjective by healthy vegetarians (n=56, lacto and lactoovo) and compared with values in subjects on a traditional diet (n=60, general population, control group). The serum iron level in vegetarian and non-vegetarian men is similar, but the frequency of deficient values is twice as high in vegetarians. The mean iron value in vegetarian women is significantly lower and deficient values were recorded in 28% of persons vs. 11 % in the control group. Deficient iron values significantly inversely correlated with the period of vegetarianism. The higher incidence of deficient iron levels in vegetarians is a consequence of the higher consumption of iron absorption inhibitors (phytic acid, oxalic acid, fibre), which are generaly present in plant food. Sideropenic anaemia was detected in 70 % of iron deficient vegetarians (microcytic hypochromic – lower erythrocyte mean volume, lower haemoglobin content in erythrocytes and lower colour concentration). Plant food sources lack vitamin B12. Levels of this vitamin are significantly decreased in vegetarians; deficient values were found in 48 % of subjects on an alternative diet vs. 8 % in the traditional group. Deficient vitamin B12 values shown a significant negative correlation with the duration of vegetarianism. Macrocytic megaloblastic anaemia occurred in 42 % of B12 deficient vegetarians (above normal mean erythrocyte volume, higher haemoglobin content in erythrocytes and low erythrocyte count). The alternative nutrition group had a significantly higher folic acid concentrations as a consequence of higher and regular consumption of vegetables, dark grain products, grain sprouts, pulses and oil seeds. Deficient values were found in 23 % of traditional nutrition group vs. 2 % in vegetarians. In the general population group, megaloblastic anaemia was present in 22%of folic acid deficient persons. The results documented a significant role of nutrition in anaemia prevention. A balance of animal/plant food consumption is important.

        Key words: iron, vitamin B12, folic acid, anaemia.