Lower bone mineral density in Somali women living in Sweden compared with African-Americans

Vitamin D deficiency can lead to osteomalacia. Bone mineral density was lower in Somali women, living in Sweden, in relation to both the American and the African-American reference populations. The majority, 73 %, had vitamin D deficiency, and supplementation should be considered to prevent from osteomalacia, osteoporosis and future fractures. Purpose Low vitamin D can lead to osteomalacia. The hypothesis was that bone mineral density (BMD) in Somali women living in Sweden was lower in comparison with different ethnic reference populations. Methods Women from Somalia, n=67, median age 35.8 years (range 18 to 56), latitude 0-10 degrees North living in Gothenburg, Sweden, latitude 57 degrees North, >2 years were studied. All wore traditional Islamic clothing and had skin photo type V. BMD was recorded as the Z-score and compared with white American and African-American women, respectively, using standard data from the dual energy X-ray absorptiometry (DXA) manufacturer (Lunar Prodigy enCORETM, GE Healthcare, LU44663). A fasting blood test was drawn for analysis of serum 25(OH) D. Results The median Z-score compared with the American white population was -0.9 SD of the lumbar spine (p<0.00001), 0.1 SD of the left hip and 0.0 SD of the right hip (ns). The median Z-score compared with the African-American population was -1.6 SD of the lumbar spine (p<0.00001), -0.9 SD of the left hip and -0.9 SD of the right hip (p<0.001). The majority, 73 %, had vitamin D deficiency, serum 25(OH) D <25 nmol/l (<10 ng/ml). BMD did not correlate to vitamin D levels or to the number of years in Sweden. One wrist fracture was reported. Conclusions BMD was lower in these fairly young immigrant women from Somalia, living in Sweden, in relation to both the American and the African-American reference populations. Vitamin D supplementation should be considered to prevent from osteomalacia, osteoporosis and future fractures.