Is Vitamin D really the key to increasing your bone density?
Vitamin D is a hormone which can be made in your skin by sunlight exposure. It is also found in certain foods. Low Vitamin D levels can be harmful to bone health 1. Health Canada recommends people aged 2-50 years old incorporate foods containing Vitamin D like salmon, egg yolk, and certain fortified milks and juices 1 into their diet. For those over 50 or those aged 2-50 who do not consume these foods, a 400 IU (low-dose) Vitamin D supplement is recommended 2.
Despite this, the consensus across several studies3,4 is that Vitamin D alone or in combination with calcium cannot improve bone density or reduce fracture risk in people who already get enough. In fact, Vitamin D can cause more harm than good when taken in excess. Vitamin D serves to increase calcium in your blood – not necessarily your bones. While it can promote more calcium absorption from your diet, it also works to release calcium from your bones, meaning that you could actually lose rather than gain bone density by taking too much 5. Not only this, but all the extra calcium in your bloodstream can accumulate in your blood vessels and in important organs like your brain or kidneys and cause rare but serious adverse effects 6.
In the end, getting enough Vitamin D is only one of many key factors to promoting strong bones. Getting enough calcium and perhaps even more importantly, enough exercise, is critical to promoting bone health 7.
If you are considering Vitamin D supplements or wondering about your osteoporosis risk, talk to your doctor. If you are already taking a Vitamin D supplement as prescribed by your registered healthcare professional, it is important that you take the recommended dose. It is also important to note that using alternative approaches such as tanning beds to increase Vitamin D levels pose considerable health risks including increased skin cancer 8 and should not be viewed as a substitute to an adequate diet and physical activity.
References:
1: Amrein K, Scherkl M, Hoffmann M, Neuwersch-Sommeregger S, Köstenberger M, Tmava Berisha A, Martucci G, Pilz S, Malle O. Vitamin D deficiency 2.0: an update on the current status worldwide. Eur J Clin Nutr. 2020 Nov;74(11):1498-1513. doi: 10.1038/s41430-020-0558-y. Epub 2020 Jan 20. PMID: 31959942; PMCID: PMC7091696.
2: Government of Canada. Vitamin D. 2022. Accessed September 28, 2025 from https://www.canada.ca/en/health-canada/services/nutrients/vitamin-d.html.
3: Méndez-Sánchez L, Clark P, Winzenberg TM, Tugwell P, Correa-Burrows P, Costello R. Calcium and vitamin D for increasing bone mineral density in premenopausal women. Cochrane Database Syst Rev. 2023 Jan 27;1(1):CD012664. doi: 10.1002/14651858.CD012664.pub2. PMID: 36705288; PMCID: PMC9881395.
4: Reis AR, Santos RKF, Dos Santos CB, Santos BDC, de Carvalho GB, Brandão-Lima PN, de Oliveira E Silva AM, Pires LV. Supplementation of vitamin D isolated or calcium-associated with bone remodeling and fracture risk in postmenopausal women without osteoporosis: A systematic review of randomized clinical trials. Nutrition. 2023 Dec;116:112151. doi: 10.1016/j.nut.2023.112151. Epub 2023 Jul 6. PMID: 37544189.
5: Burt LA, Billington EO, Rose MS, Raymond DA, Hanley DA, Boyd SK. Effect of High-Dose Vitamin D Supplementation on Volumetric Bone Density and Bone Strength: A Randomized Clinical Trial. JAMA. 2019 Aug 27;322(8):736-745. doi: 10.1001/jama.2019.11889. Erratum in: JAMA. 2019 Nov 19;322(19):1925. doi: 10.1001/jama.2019.17910. PMID: 31454046; PMCID: PMC6714464.
6: Marcinowska-Suchowierska E, Kupisz-Urbańska M, Łukaszkiewicz J, Płudowski P, Jones G. Vitamin D Toxicity-A Clinical Perspective. Front Endocrinol (Lausanne). 2018 Sep 20;9:550. doi: 10.3389/fendo.2018.00550. PMID: 30294301; PMCID: PMC6158375.
7: Kemmler W, Shojaa M, Kohl M, von Stengel S. Effects of Different Types of Exercise on Bone Mineral Density in Postmenopausal Women: A Systematic Review and Meta-analysis. Calcif Tissue Int. 2020 Nov;107(5):409-439. doi: 10.1007/s00223-020-00744-w. Epub 2020 Aug 12. PMID: 32785775; PMCID: PMC7546993.
8: An S, Kim K, Moon S, Ko KP, Kim I, Lee JE, Park SK. Indoor Tanning and the Risk of Overall and Early-Onset Melanoma and Non-Melanoma Skin Cancer: Systematic Review and Meta-Analysis. Cancers (Basel). 2021 Nov 25;13(23):5940. doi: 10.3390/cancers13235940. PMID: 34885049; PMCID: PMC8656707.