Objective: The study was designed to evaluate the vitamin D status in women of different physiological status of two socio-economic groups in Bangladesh.

Design: A cross-sectional study, using serum 25-hydroxyvitamin D (25-OHD), calcium, phosphorus and alkaline phosphatase activity.

Setting: Two regions of Bangladesh. The Dhaka city area and west region of Nandail (Betagair Union), Mymensingh.

Subjects: Representative subjects of two groups (low socio-economic group=group L, n=99; and high socio-economic group=group H, n=90) of Bangladeshi women aged 16-40 y. About 87% of the subjects were housewives and the rest, 13%, were distributed among other different professions. Each group comprised of three sub-groups (non-pregnant non-lactating=1, pregnant=2, and lactating=3).

Results: The influence of socio-economic status and physiological status on serum 25-OHD concentration (P=0.038, P=0.015, respectively), serum calcium concentration (P<0.001, P<0.001, respectively) and alkaline phosphatase activity (P<0.001, P<0.001, respectively) were observed. The distribution of serum 25-OHD concentration in both groups was shifted overall toward the lower limit of the normal range. Seventeen percent of women in group L and 12% of women in group H had serum 25-OHD concentration <25 nmol/l. Hypovitaminosis D (serum 25-OHD concentration < or = 37.5 nmol/l) was observed in 50% of subjects in group L and 38% of subjects in group H, respectively. The prevalence of hypovitaminosis was higher in lactating subjects of the groups L and H (63 and 46%, respectively) than in the other sub-groups in the same group.

Conclusions: The results of the study suggested that women in Bangladesh were at risk of hypovitaminosis D and lactation was an additional risk factor in low income groups. The situation may increase the risk of bone loss.