In this 2-year randomized controlled study of 1.67 men > 50 years of age, supplementation with calcium-vitamin D-3-fortified milk providing an additional 1000 mg of calcium and 800 IU of vitamin D-3 per day was effective for suppressing PTH and stopping or slowing bone loss at several clinically important skeletal sites at risk for fracture. Introduction: Low dietary calcium and inadequate vitamin D stores have long been implicated in age-related bone loss and osteoporosis. The aim of this study was to assess the effects of calcium and vitamin D-3 fortified milk on BMD in community living men > 50 years of: age. Materials and Methods: This was a 2-year randomized controlled study in which 167 men (mean age +/- SD 61.9 +/- 7.7 years) were assigned to receive either 400 ml/day of reduced fat (similar to 1%) ultra-high temperature (UHT) milk containing 1000 mg of calcium plus 800 IU of vitamin D-3 or to a control group receiving no additional milk. Primary endpoints were changes in BMD, serum 25(OH)D, and PTH. Results: One hundred forty-nine men completed the Study. Baseline characteristics between the groups were not different; mean dietary calcium and serum 25(OH)D levels were 941 +/- 387 mg/day and 77 +/- 23 W, respectively. After 2 years, the mean percent change in BMD was 0.9-1.6% less in the milk supplementation compared with control group at the femoral neck, total hip, and ultradistal radius (range, p < 0.08 top < 0.001 after adjusting for covariates). There was a greater increase in lumbar spine BMD in the milk supplementation group after 12 and 18 months (0.8-1.0%, p <= 0.05). but the between-group difference was not significant after 2 years (0.7%; 95% CI. -0.3, 1.7). Serum 25(OH)D increased and PTH decreased in the milk supplementation relative to control group after the first year (31% and -18%, respectively; both p < 0.001), and these differences remained after 2 years. Body weight remained unchanged in both groups at the completion of the study. Conclusions: Supplementing the diet of men > 50 years of age with reduced-fat calcium- and vitamin D-3- enriched milk may represent a simple, nutritionally sound and cost-effective strategy to reduce age-related bone loss at several skeletal sites at risk for fracture in the elderly.