ABSTRACT
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.
Subject(s)
Calcifediol/blood , Femoral Neck Fractures/etiology , Sunlight , Adult , Age Factors , Aged , Alkaline Phosphatase/blood , Ethnicity , Female , Femoral Neck Fractures/blood , Femoral Neck Fractures/enzymology , Femoral Neck Fractures/epidemiology , Housing , Humans , Male , Middle Aged , Saudi Arabia , Sex Factors , Ultraviolet RaysABSTRACT
Serum levels of the circulating form of vitamin D3, 25-hydroxycholecalciferol [25-(OH)D3], were determined in 59 university students, 26 males and 33 females, aged 18 to 26 yr and in 24 elderly subjects, 13 males and 11 females, with a mean age of 62 +/- 13 yr. The level of 25-(OH)D3 was significantly lower in the elderly persons (p less than 0.001) than in young students of both sexes, and was significantly higher in females than in males. Serum levels of 1, 25- and 24, 25-dihydroxycholecalciferol were measured in adult males and found to be within the normal range. A group of elderly patients were exposed to natural uv light, and the circulating levels of 25-(OH)D3, serum phosphorus, and alkaline phosphatase were determined both before and 1 day after the last exposure. The exposure to natural uv light resulted in a 2 1/2-fold increase in the level of 25-(OH)D3 and a significant decrease in the activity of alkaline phosphatase, but no significant change in serum phosphorus concentrations was observed. It is concluded that the low vitamin D3 status in Saudis is mainly due to avoidance of sunlight exposure and other factors discussed below.
