Vitamin D status in healthy Egyptian adolescent girls

Over the last decade there had been growing evidence of high prevalence of vitamin D deficiency especially among adolescents. Inadequate sun exposure is considered a precipitating factor. Females who remain fully covered seem to be at greatest risk. The aim of this study was to investigate the vitamin D status in adolescent females in Egypt. Seventy five healthy adolescent girls aged 14-17 years were recruited during the summer months. Anthropometric measures, calcium and vitamin D intake, sun exposure index, use of topical sun screen, and socioeconomic standard were all determined. Serum calcium, inorganic phosphate, alkaline phosphatase, and 25 hydroxycholecalceferol (25-OHD) were measured. Sixteen girls (21.3 %) had vitamin D deficiency, 18 were vitamin D insufficient (24 %), and 41 had adequate vitamin D levels (54.7 %). Both sun exposure index and daily sun exposure time were significantly higher in girls with adequate vitamin D levels compared to those with insufficient and deficient vitamin D. Exposure of at least 18% of BSA for at least 37 minutes/day is enough to achieve adequate vitamin D levels in a sunny climate as Egypt. Calcium intake was highest in girls with adequate 25-OHD, while there was no difference in vitamin D intake. Serum 25-OHD correlated positively with BMI, BMI standard deviation score (SDS), sun exposure index, sun exposure time, and daily calcium intake, and negatively with PTH level. Vitamin D deficiency is a common problem among Egyptian adolescent girls. Inadequate sun exposure, possibly related to cultural/social factors influence vitamin D levels. Insufficient dietary calcium is another contributing factor.