Authors: Dr. Marie-Josée Bégin, Dr. Claudia Gagnon, Dr. Alan Low, Dr. Shirine Usmani, Dr. Vithika Sivabalasundaram, Dr. Laetitia Michou, Dr. Adrian Lau
Earlier this year, a Canadian review (1) reported that calcium and vitamin D supplements had little or no benefit in preventing fractures or falls. These results have renewed attention to the role of vitamin D and calcium supplementation in bone health and fuels the concerns of some healthcare professionals and patients.
It is important to understand who was included in these studies. Most of the research involved older adults living independently who were generally not at high risk of fractures and often already had normal vitamin D levels. The results do not apply to people living with osteoporosis, such as those who have already had a fragility fracture, are taking osteoporosis medication, or are at high risk of vitamin D deficiency.
In fact, when calcium and vitamin D were taken together, they were associated with about a 9% lower risk of fractures. This benefit suggests that calcium and vitamin D play a role in maintaining bone health.
Vitamin D is essential to help the absorption of calcium and phosphorus, two minerals that are essential for maintaining strong bones and healthy muscles. Health Canada and Osteoporosis Canada (2) recommend that adults over the age of 50 get enough calcium and vitamin D every day.
Table 1. Recommended dietary allowance of calcium and vitamin D
| Males 51–70 yr | Males > 70 yr | Females 51–70 yr | Females > 70 yr | |
|---|---|---|---|---|
| Calcium/day | 1000 mg | 1200 mg | 1200 mg | 1200 mg |
| Vitamin D/day | 600 IU | 800 IU | 600 IU | 800 IU |
Because few foods contain vitamin D and it could be difficult to achieve this level, Health Canada recommends a daily vitamin D supplement of 400 IU in adults over 50, in addition to eating vitamin D–rich foods. Some people may need a higher dose if they are at increased risk of vitamin D deficiency (2).
Table 2. Risk factors for vitamin D insufficiency/deficiency according to Osteoporosis Canada guidelines2
| Malabsorption syndromes (e.g. inflammatory bowel disease, celiac disease, bariatric surgery, gastrectomy) |
| Reduced skin synthesis (e.g. limited sun exposure, increased skin pigmentation) |
| Liver failure/cirrhosis |
| Nephrotic syndrome |
| Chronic kidney disease/renal failure |
| Medication affecting vitamin D metabolism (e.g. anticonvulsants, glucocorticoids, antiretroviral agents) |
| Parathyroid disorders (e.g. hypoparathyroidism, hyperparathyroidism) |
Take-home message
It is important to remember that recent studies often do not apply to individuals living with osteoporosis, who have had previous fragility fractures, who are on anti-osteoporotic medication, or those with a condition associated with a high risk of vitamin D deficiency.
Individuals are encouraged to seek advice from healthcare professionals regarding vitamin D and calcium supplementation before making any changes to their habits. Calcium and vitamin D supplements should be individualized based on the diet, health, and medical conditions.
Learn more about vitamin D and calcium supplements in the nutrition section.
References
1. Massé O, Mercurio CM, Dupuis S, Al Sahwi M, Arruda A, Dallaire G, et al. Calcium, vitamin D, or combined supplementation to prevent fractures and falls: systematic review and meta-analysis. BMJ. 2026;393:e088050.
2. Morin SN, Feldman S, Funnell L, Giangregorio L, Kim S, McDonald-Blumer H, et al. Clinical practice guideline for management of osteoporosis and fracture prevention in Canada: 2023 update. CMAJ. 2023;195(39):E1333-e48.
Scientific Advisory Council
Osteoporosis Canada’s rapid response team, made up of members of the Scientific Advisory Council, creates position statements as news breaks regarding osteoporosis. The position statements are used to inform both the healthcare professional and the patient. The Scientific Advisory Council (SAC) is made up of experts in Osteoporosis and bone metabolism and is a volunteer membership.
