Total plasma homocysteine, folate, and vitamin b12 status in healthy Iranian adults: the Tehran homocysteine survey (2003-2004)/a cross-sectional population based study

Background: Elevated plasma total homocysteine is an independent risk factor for cardiovascular disease and a sensitive marker of the inadequate vitamin B12 and folate insufficiency. Folate and vitamin B12 have a protective effect on cardiovascular disease. This population based study was conducted to evaluate the plasma total homocysteine, folate, and vitamin B12 in healthy Iranian individuals. Methods: This study was a part of the Cardiovascular Risk Factors Survey in the Population Lab Region of Tehran University has been designed and conducted based on the methodology of MONICA/WHO Project. A total of 1214 people aged 25-64 years, were recruited and assessed regarding demographic characteristics, homocysteine, folate, and vitamin B12 levels with interview, questionnaires, examination and blood sampling. Blood samples were gathered and analyzed according to standard methods. Results: The variables were assessed in 1214 participants including 428 men (35.3%) and 786 women (64.7%). Age-adjusted prevalence of hyperhomocysteinemia (Hcy >= 15 mu mol/L) was 73.1% in men and 41.07% in women (P < 0.0001). Geometric mean of plasma homocysteine was 19.02 +/- 1.46 mu mol/l in men and 14.05 +/- 1.45 mu mol/l in women (P < 0.004) which increased by ageing. Age-adjusted prevalence of low serum folate level was 98.67% in men and 97.92% in women. Age-adjusted prevalence of low serum vitamin B12 level was 26.32% in men and 27.2% in women. Correlation coefficients (Pearson's r) between log tHcy and serum folate, and vitamin B12 indicated an inverse correlation (r = -0.27, r = -0.19, P < 0.0001, respectively). Conclusion: These results revealed that the prevalence of hyperhomocysteinemia, low folate and vitamin B12 levels are considerably higher than other communities. Implementation of preventive interventions such as food fortification with folic acid is necessary.