The report evaluating this message is mainly based on a 2017 systematic review. It looked at the effects of calcium supplementation for fracture prevention in people over 50 years of age living at home (not in nursing homes). The review included 14 clinical trials with a total of 7,706 people in which the risk of hip, vertebral, non-vertebral, or any type of fracture was studied.   

The scientific research published to date on the efficacy of calcium and/or vitamin D supplements in reducing fractures is a controversial topic. As García-Franco and colleagues explain, there are clinical trials and systematic reviews showing the efficacy of vitamin D, of calcium with or without vitamin D, and of the joint administration of calcium and vitamin D. There are other studies that do not find favourable results, and support the statement that «it is not effective to give calcium and vitamin D supplements in the general population over 50 years of age».    

Again, some later reviews agree. In 2018, the United States Preventive Services Task Force (USPSTF) concluded that the current evidence is insufficient to assess the balance of benefits and harms of vitamin D and calcium supplementation, alone or in combination, for the primary prevention of fractures in asymptomatic men and premenopausal women.   

Even earlier reviews, such as that of Tai V et al. in 2015, already stated that the effects on bone mass density of increased calcium intake are similar for dietary or supplement sources (a 1 % increase during the first year of use, with no subsequent increases), are independent of vitamin D co-administration, and are not related to the initial dietary calcium intake or the dose of calcium used.    

Therefore, for most people who may be concerned about their bone mass density, increased calcium intake from supplements is unlikely to be beneficial.   

As for as bone fracture prevention is concerned, for the general population over the age of 50, the current recommendation is to «take the recommended daily intake of calcium from the diet and accompany it with a daily dose of sun exposure and physical exercise».   

Things are different for people who already suffer from osteoporosis, for whom we have to use all the help we can get—and even then it may not be enough. According to a 2021 review, «there is now scientific evidence to justify the need to treat all patients with osteoporosis and vitamin D deficiency with calcium and vitamin D (preferably cholecalciferol), regardless of the treatment they receive for osteoporosis. The daily dose of cholecalciferol to be used should be at least 2,000 IU (international units).