BIOSOCIAL FACTORS AFFECTING VITAMIN-D STATUS OF WOMEN OF CHILDBEARINGAGE IN THE UNITED-ARAB-EMIRATES

Low serum 25-OHD in female Arab subjects, which may predispose their i nfants to hypocalcaemia, has been suggested to be due to inadequate su nshine exposure, but may include other sociobiological factors. The ef fects of duration of sunshine exposure - weighted against the magnitud e of clothing (UV exposure) and other sociobiological variables such a s age, education and living accommodation - on serum 25-OHD and minera l status of 33 UAE national women of childbearing age were compared wi th those of 25 non-Gulf Arabs and seventeen Europeans. Serum concentra tions of calcium, phosphorus, alkaline phosphatase and intact parathyr oid hormone among the groups were not significantly different. The ser um concentration of 25-OHD in UAE nationals was 8.6 ng/ml (4.5-17.4), mean +/- 1 SD, and in non-Gulf Arabs 12.6 ng/ml (6.0-26.4); both these values were significantly lower (p = <0.0001) than the 64.3 ng/ml (49 -84.3) found in Europeans. Compared with Europeans, the UAE and non-Gu lf Arabs in this study were younger, had fewer years of education and had significantly lower clothing and UV scores (p < 0.0001). Furthermo re, there was a positive correlation (r = 0.59425) between serum 25-OH D and UV score, but not with length of exposure. After adjusting for o ther confounding variables, nationality, clothing and UV scores remain ed major determinants of serum 25-OHD (p < 0.0001). Therefore, limited skin exposure to sunlight appears to be an important determinant of v itamin D status in our subjects. Strategies to increase vitamin D stor es should include vitamin D supplementation or advice on effective sun light exposure.