The skeletal benefits of calcium- and vitamin D3–fortified milk are sustained in older men after withdrawal of supplementation: an 18-mo follow-up study

Abstract

Background: In a previous 2-y randomized controlled trial, we showed that calcium- and vitamin D3–fortified milk stopped or slowed bone loss at several clinically relevant skeletal sites in older men.Objective: The present study aimed to determine whether the skeletal benefits of the fortified milk were sustained after withdrawal of the supplementation.Design: One hundred nine men >50 y old who had completed a 2-y fortified milk trial were followed for an additional 18 mo, during which no fortified milk was provided. Bone mineral density (BMD) of the total hip, femoral neck, lumbar spine, and forearm was measured by using dual-energy X-ray absorptiometry.Results: Comparison of the mean changes from baseline between the groups (adjusted for baseline age, BMD, total calcium intake, and change in weight) showed that the net beneficial effects of fortified milk on femoral neck and ultradistal radius BMD at the end of the intervention (1.8% and 1.5%, respectively; P < 0.01 for both) were sustained at 18-mo follow-up (P < 0.05 for both). The nonsignificant between-group differences at the total hip (0.8%; P = 0.17) also persisted at follow-up (0.7%; P = 0.10), but there were no lasting benefits at the lumbar spine. The average total dietary calcium intake in the milk supplementation group at follow-up approximated recommended amounts for Australian men >50 y old (1000 mg/d) but did not differ significantly from that in the control subjects (1021 versus 890 mg/d).Conclusion: Supplementation with calcium- and vitamin D3–fortified milk for 2 y may provide some sustained benefits for BMD in older men after withdrawal of supplementation.