Assessment of folate status:: Measurement of homocysteine versus vitamin B12 and folate

This study was based on 63 subjects (mean age 50 9) including 41 patients with clinical and objective investigational evidence of vascular disease (age 30 30-66 years) and 22 control subjects (age 26-54 years). Dietary intake of folate was estimated from a food questionnaire of folate (Q.folate). There was no statistically significant difference between controls and patients for dietary folate. Also the plasma folate level did did noly slightly differ between the controls and patients (6.68 +/- 2.52 ng/mL versus 5.62 +/- 4.16 ng/mL, not significant). Patients had higher average homocysteine concentrations than control subjects (12.93 +/- 8.79 vs 9.07 +/- 3.08 mumol/l, p<0.05). A significant relationship was observed in controls between plasma folate concentrations and the homocysteine levels (rs = - 0.538; p<0.01), and the folate questionnaire (rs = 0.697; p<0.001). We found in controls significant positive correlation between vitamin B12 and vitamin B6 (rs = 0.475, p<0.05). By contrast, no association was found in patients between folate and homocysteine concentrations and the dietary nutrient intake of folate. On the other hand vitamin B12 is inversely associated with homocysteine (rs = -0.333, p<0.05). These data provide further evidence that plasma homocysteine is an independent risk factor for myocardial infraction. Homocysteine is a valuable functional index of micronutrient status and intakes for people, which can assist the development of the public health. In our population, folate was the most important determinant of plasma homocysteine, even in subjects with apparently adequate nutritional status of this vitamin.