Two recent BMJ analyses showed little benefit from calcium supplementation in older patients, and that the side effects of calcium supplementation (kidney stones and cardiovascular problems) outweighed the benefits. A systematic review of calcium supplementation and fracture risk To examine whether calcium supplementation through diet or calcium tablets can prevent fractures, the investigators conducted a systematic review of randomized controlled and observational studies of calcium supplementation with fracture as an endpoint. Calcium supplementation included dietary calcium, milk or milk products, and calcium tablets (with or without vitamin D) in subjects >50 years of age. For dietary calcium, most studies showed no association between calcium intake and fracture. For milk and dairy supplementation, most studies also showed no association. In 26 randomized controlled studies, calcium supplementation reduced the risk of overall fracture (20 studies, n=58573; relative risk 0.89, 95% CI 0.81 to 0.96) and vertebral fracture (12 studies, n=48967; 0.86, 0.74 to 1.00) but not hip fracture (13 studies, n=56648; 0.95 , 0.76 to 1.18) or risk of forearm fracture (8 studies, n=51775; 0.96, 0.85 to 1.09). Funnel plot tests and linear regression (Egger’s regression) suggested a bias in favor of calcium supplementation in these published data. The randomized clinical trial with the lowest possible bias (4 studies, n=44505) suggested no effect on fracture risk reduction at any site. Results were similar for calcium supplementation alone and studies with both calcium and vitamin D supplementation. Only one study of frail older women in community care homes with low dietary calcium intake and vitamin D deficiency showed a significant reduction in fracture risk. This study showed that dietary calcium intake was not associated with fracture risk and that there was no clinical evidence for increased dietary calcium intake to prevent fractures. The evidence for fracture prevention with calcium tablets is weak and inconsistent. A systematic review and meta-analysis of calcium supplementation and bone mineral density To determine the effect of increased dietary calcium intake on bone mineral density and whether the effect, if any, was consistent with taking calcium tablets, the investigators conducted a meta-analysis of randomized controlled trials. Dietary sources of calcium and calcium tablets (with or without vitamin D) were included, subjects were >50 years of age, and bone mineral density included the lumbar spine, hip, femoral neck, whole body, or forearm. A total of 59 randomized controlled trials: 15 studied dietary calcium (n=1533) and 51 studied calcium tablets (n=12257). Dietary calcium intake increased bone mineral density in the hip and whole body by 0.6 to 1.0% after 1 year, and by 0.7 to 1.8% at these sites and in the lumbar spine and femoral neck after 2 years. There was no change in forearm bone mineral density. Bone mineral density increased by 0.7 to 1.8% at all five skeletal sites after 1, 2, and 2.5 years of calcium tablets, and the increase in bone mineral density was similar to that after 1 year of taking calcium tablets for a longer period of time. Bone mineral density increased similarly (except in the forearm) with dietary calcium supplementation compared with taking calcium tablets, calcium alone compared with both calcium and vitamin D supplementation, calcium tablet doses ≥1000 mg per day compared with <1000 500="">500 mg per day, and dietary calcium intake <800 mg per day at baseline compared with ≥800 mg per day. This study suggests that a slight and non-progressive improvement in bone mineral density from increased calcium intake via diet or calcium tablets is unlikely to result in a reduction in clinical fracture risk.