To determine whether elderly patients presenting with a fracture of the proximal femur have an underlying vitamin D deficiency. We identified 59 consecutive cases of a fracture of the proximal femur over a 10-week period. 16 patients were excluded as they had a secondary underlying cause of bone loss which included chronic renal disease, rheumatoid arthritis, thyroid/parathyroid disorders, long term steroid usage and malignancy. Of the 43 that were eligible for the study, 7 were men and the average age was 81 years. 9 had sustained previous osteoporotic fractures. The majority mobilised independently or with 1 stick prior to the fall and the mechanism in all cases was a low velocity injury from standing height or less. The mean vitamin D3 level in these cases was 28. 3 nmol/ l. 28 of the 43 had a pathologically low level of vitamin D3 as defined as <
30nmol/l. The mean PTH level was 53. 7 nmol/ l. 15 of the 43 had an elevated PTH and all 15 were also deficient in vitamin D. The mean Albumin, an indicator of nutritional status, was 29 g/l. This study highlights that 65% of the patients who present with a fracture of the proximal femur are depleted in vitamin D. The ageing process is associated with a reduction in the intake of vitamin D, gut absorption and its sunlight activation. Repletion of vitamin D and suppression of parathyroid hormone, both prophylactically or at the time of injury, may reduce future fracture risk and assist in fracture repair.