Is avoidance of sunlight a cause of fractures of the femoral neck in elderly Saudis?

A study of the frequency of admitted cases of femoral neck fractures to Riyadh Central Hospital, Riyadh, Saudi Arabia, showed admission of 95 patients over 40 years of age in a period of one year. The male to female ratio was 64% males to 36% females. Vitamin D nutritional status of patients with fractures of the neck of the femur expressed as 25-(OH)D3 was significantly lower (5.9 +/- 2.9 ng/ml) than of controls (9.7 +/- 4.7 ng/ml). Comparison of the housing types of both patients and controls showed that those living in traditional mud houses have significantly lower levels of 25-(OH)D3 than those occupying villas or flats. A third group of patients with low stores of vitamin D were exposed to natural ultraviolet light for a short period. This resulted in a significant increase in the levels of serum 25-(OH)D3 and a decrease in alkaline phosphatase activity. It is concluded that low levels of serum 25-(OH)D3 may play a role in the pathogenesis of femoral neck fractures in elderly Saudis and this may be due to minimal exposure to natural ultraviolet irradiation.