Objectives: The purpose is to research the way vegetarian nourishemnt, yoga excercise and the MTHFR C 677/T polymorphism influence the value of hematological, biochemical and physical parameters, and the concentration of homocysteines, folates and vitamin B12 present in the blood. Patients and methods: The reasearch has covered 100 examinees: 47 vegetarians and 53 nonvegetarians; 54 of them have been practicing yoga, while 46 have not. Beside the anamnestic data, the examinees have been determinated on anthropometric, hematological and biochemical parameters, while the concentration of homocysteines, folates and vitamin B12 has been validated with the Architect (Abbott, USA) automatized immuno analyzer. Every examinee in the research has had the MTHFR C677T genotype polymorphism analyzed with the PCR-RFLP method. The method used for the analysis of quality-of-life have been queries: Perceived stress scale and the SF 36 health questionnaire. Results: The research has determined that vegetarian examinees have a significant lower vitamin B12 level, a lower cholesterol, LDL-cholesteral and creatinine level, a higher level of homocysteines, a better quality of life, are more content with their physical and mental health, consequently, their total health in regards to the normative group. The examinees who practice yoga have a significant lower value of creatinine and a better quality of life, are more content with their physical and total health in regards to the normative group. The perceived stress scale has not given any significant difference, although the vegetarian examinees and the ones practicing yoga perceive less stress than the normative group. The MTHFR C677T genotype mutation frequency: examinees that are not carriers od the mutation (44%), (43%) and homozygous carriers (13%). The vegetarian heterozygous status affect the level of homocysteine, but does not affect the level of vitamin B12 and folic acid, while vegetarian VIII nutrition statistically significantly lowers the level of homocysteine and vitamin B12. The homozygous status does not explain the level of homocysteine, possible because of the small number of examinees, but statistically significantly, sex and nutrition do. The male sex and vegetarian nutrition are statistically significant predictors of a higher level of homocysteine. Conclusions: This reaserch has showed that vegetarian diet and the vegetarian heterozygous status MTHFR 677C/T infulences the level of homocysteine. The vegetarian nourishment has been shown as a significant factor of physical parameters of health, as for the self-evaluation of the quality-of-life. The results of the research are contributing to the explanation of the factors that influence the level of homocysteine and are pointing out the need for an additional research on the C677T MTHFR polymorphism and its influence on the vitamin B12, folate and homocysteine status.