Conflicting opinions are held on the efficacy and safety of low-dose oral vitamin D supplementation. In this study, the value of short-term and long-term low-dose vitamin D supplementation (20 μg D3 daily) is demonstrated in elderly subjects. Short-term therapy readily restored serum 25-hydroxy-vitamin D (25OHD) values to normal, and ameliorated biochemical abnormalities of calcium, phosphate, and alkaline phosphatase, consistent with healing of mild osteomalacia. Prolonged therapy (16 months) maintained serum 25OHD levels within the young adult range, and was not associated with hypercalcemia. Withdrawal of therapy was associated with a steady decline in serum 25OHD levels. Low-dose vitamin D supplementation is recommended for elderly subjects to prevent the development of hypovitaminosis D osteopathy.