Abstract
In a series of 134 iliac-crest biopsies from unselected cases of fracture of the proximal femur, the proportion with evidence of osteomalacia varied with the season. The highest frequency of abnormal calcification fronts (43%) was observed in February to April and the lowest (15%) in August to October. The highest frequency of abnormal osteoid-covered surfaces (47%) was observed in April to June and the lowest (13%) in October to December. The overall frequency of osteomalacia in femoral-neck-fracture cases in Leeds seems to be about 37%. It is concluded that variation in hours of sunshine is responsible for a seasonal variation in osteomalacia in these cases and, possibly, in the elderly population as a whole.