Folate and vitamin B-12 status of adolescent girls in northern Nigeria

The diets of populations in many developing countries are low in folate and vitamin B-12 and a deficiency of either of these vitamins results in incre ased risk for cardiovascular disease and neural tube defects. The rates of neural tube defects in Nigeria are among the highest reported worldwide. Si nce many girls marry at an early age in northern Nigeria, we therefore dete rmined the folate and vitamin B-12 status of adolescent girls between 12 an d 16 years of age in Maiduguri, Nigeria. The mean serum folate concentratio n for subjects was 15.3 +/- 5.2 nmol/L. Whereas only Four subjects (2.4%) h ad serum folate concentrations lower than 6.8 nmol/L, a level indicative of negative folate balance, 9% of the subjects had serum vitamin B-12 concent rations at or below 134 pmol/l, the lower limit of the reference range for their age group. Serum homocysteine was measured in 56 of the 162 subjects and the mean level was 15.9 +/- 5.0 mu mol/L. The majority of subjects had serum homocysteine concentrations above the upper limit of the reference ra nge for their age group. We conclude that the adolescent girls we studied w ere at greater risk for vitamin B-12 deficiency than folate deficiency. Thi s conclusion is consistent with the fact that their diet included few foods that contained vitamin B-12.