Biosocial factors affecting vitamin D status of women of childbearing age in the United Arab Emirates

J Biosoc Sci. 1998 Oct;30(4):431-7. doi: 10.1017/s0021932098004313.


Low serum 25-OHD in female Arab subjects, which may predispose their infants to hypocalcaemia, has been suggested to be due to inadequate sunshine exposure, but may include other sociobiological factors. The effects of duration of sunshine exposure--weighted against the magnitude of clothing (UV exposure) and other sociobiological variables such as age, education and living accommodation--on serum 25-OHD and mineral status of 33 UAE national women of childbearing age were compared with those of 25 non-Gulf Arabs and seventeen Europeans. Serum concentrations of calcium, phosphorus, alkaline phosphatase and intact parathyroid hormone among the groups were not significantly different. The serum 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-Gulf Arabs in this study were younger, had fewer years of education and had significantly lower clothing and UV scores (p < 0.0001). Furthermore, there was a positive correlation (r = 0.59425) between serum 25-OHD and UV score, but not with length of exposure. After adjusting for other confounding variables, nationality, clothing and UV scores remained major determinants of serum 25-OHD (p < 0.0001). Therefore, limited skin exposure to sunlight appears to be an important determinant of vitamin D status in our subjects. Strategies to increase vitamin D stores should include vitamin D supplementation or advice on effective sunlight exposure.

PIP: Maternal vitamin D deficiency can aggravate development of neonatal hypocalcemia and impair fetal bone growth. Despite abundant sunshine exposure, Arab women have low serum concentrations of 25-hydroxy vitamin D (25-OHD). A study conducted in Al Ain, United Arab Emirates (UAE), compared the vitamin D status of 33 UAE nationals, 25 non-Gulf Arabs (Jordanians, Egyptians, Palestinians, and Lebanese), and 17 Europeans. Serum concentrations of calcium, phosphorus, alkaline phosphatase, and intact parathyroid hormone were not significantly different in these three groups. However, mean serum 25-OHD concentrations were significantly lower among UAE nationals (8.6 ng/ml) and other non-Gulf Arabs (12.6 ng/ml) than in Europeans (64.3 ng/ml) (p 0.0001). The rate of vitamin D insufficiency (5 ng/ml) was 24% among UAE nationals and 12% among non-Gulf Arabs; there were no such cases among Europeans. The ultraviolet ray (UV) exposure score, which weighted sunshine exposure against the magnitude of body coverage with clothing, was significantly higher in European women than in the two Arab groups. There was a positive correlation between total UV exposure score and serum 25-OHD level (r = 0.59425). About 35% of the variation in serum 25-OHD could be explained by the cutaneous skin exposure score. The limited exposure of Arab women's skin to sunlight as a result of their traditional, extensive clothing appears to play an important role in the high frequency of low vitamin D status in this population. Vitamin D supplementation should be considered.

MeSH terms

  • Adult
  • Arabs* / psychology
  • Clothing
  • Female
  • Gender Identity*
  • Humans
  • Life Style*
  • United Arab Emirates
  • Vitamin D Deficiency / ethnology*
  • Vitamin D Deficiency / psychology