While I was contemplating what I could write for my first blog post, I was trying to think what I could offer that nobody else in the nutrition world was already providing. The conclusion that I came to was the findings of my systematic review that I did in my final year at university, on the topic of whether calcium and vitamin D supplements reduce the risk of fractures in people 50+ years old. I never published the results and I chose this subject because there had been no clear answer in the research, so I figured that it’s something that I could share that nobody else could. To keep things short and sweet, I’ll do this post on calcium first and then do a separate post on vitamin D.
The body of research has had results suggesting that calcium supplementation reduces the risk of fractures  and other results showing that it does not have a significant effect . This was quite confusing and I can see why it isn’t common knowledge about whether or not calcium supplements are effective for reducing the risk of fractures. We all have heard that “calcium builds strong bones,” so why didn’t the supplementation show this effect? The key point I found was that all the studies using less than 1200mg of calcium carbonate had no significant effect and the people that used at least 1200mg did find a reduction in the risk of fractures [3-4]. What was the most interesting thing I found was that in at least one study, a lot of the participants didn’t take the supplements as frequently as required [3-4]. This caused the study results to be insignificant, but if you looked at the people who actually took their supplements as planned, they had a reduction in their risk of fractures [3-4]. I think this is an issue that is extremely transferable to the real world. Even with the knowledge that something as simple as taking a certain dose of a supplement may reduce the risk of a serious concern, people need to be motivated to actually follow through.
Should you be taking calcium supplements? This is a difficult question to answer since it depends on the individual situation. The research showed that 1200mg of calcium carbonate reduced the risk of fractures in people aged 50 years or older, but this could be misleading since it didn’t account for calcium in the diet. Perhaps there would have been less of an effect for people who were consuming adequate calcium in their diet and more of an effect for people who didn’t consume enough.
For men aged 51-70 years old the recommended number of serves of dairy is 2 ½ and this goes up to 3 ½ when they are 70+ years old . Unluckily (or lucky for those who really enjoy dairy) women aged 50+ are recommended to have 4 serves of dairy per day . A serve of dairy is one cup of milk, two slices of cheese, ¾ cup of yoghurt or one cup of an alternative milk drink (e.g. soy) with at least 100mg of calcium. For some people these goals are pretty easy to meet, but I can definitely see why some people can’t realistically see themselves consuming four serves of dairy every day.
Alternatively, you can get your calcium from sources apart from dairy. The recommended daily intake of calcium is 1000-1300mg per day depending on your age group . Some non-dairy foods high in calcium are canned salmon with bones (230mg per can), leafy green vegetables (75mg in a cup of Bok Choy, 95mg in a cup of Kale), almonds (70mg in ¼ of a cup), oranges (65mg in one orange) and firm tofu (430mg in ¼ of a cup). It is possible to tailor your diet to make sure you are getting enough calcium without consuming dairy. However once again, I can see why people could also see that as unrealistic.
Getting the calcium from food sources is better because it has other nutritional benefits – for example the calories and protein in dairy products can help maintain muscle mass which could reduce the risk of falls [7-8]. Although food is preferable, if it is clear that you are not getting enough calcium in your diet it is likely that calcium supplementation will help maintain your bone mineral density and reduce your risk of fractures [9-11].
1. Chapuy, M. C., Arlot, M. E., Duboeuf, F., Brun, J., Crouzet, B., Arnaud, S., … & Meunier, P. J. (1992). Vitamin D3 and calcium to prevent hip fractures in elderly women. The New England Journal of Medicine, 327(23), 1637-1642.
2. Porthouse, J., Cockayne, S., King, C., Saxon, L., Steele, E., Aspray, T., … & Iglesias, C. (2005). Randomised controlled trial of calcium and supplementation with cholecalciferol (vitamin D3) for prevention of fractures in primary care. BMJ, 330(7498), 1003.
3. Prince, R. L., Devine, A., Dhaliwal, S. S., & Dick, I. M. (2006). Effects of calcium supplementation on clinical fracture and bone structure: Results of a 5-year, double-blind, placebo-controlled trial in elderly women.
4. Bischoff-Ferrari, H. A., Rees, J. R., Grau, M. V., Barry, E., Gui, J., & Baron, J. A. (2008). Effect of calcium supplementation on fracture risk: a double-blind randomized controlled trial. The American Journal of Clinical Nutrition, 87(6), 1945-1951.
5. Recommended Number of Serves for Adults, Retrieved from https://www.eatforhealth.gov.au/food-essentials/how-much-do-we-need-each-day/recommended-number-serves-adults
6. Calcium Nutrient Reference Values, Retrieved from https://www.nrv.gov.au/nutrients/calcium
7. Evans, W. J. (2004). Protein nutrition, exercise and aging. Journal of the American College of Nutrition, 23(6), 601-609.
8. LaStayo, P. C., Ewy, G. A., Pierotti, D. D., Johns, R. K., & Lindstedt, S. (2003). The positive effects of negative work: increased muscle strength and decreased fall risk in a frail elderly population. The Journals of Gerontology Series A: Biological Sciences and Medical Sciences, 58(5), 419-424.
9. Marshall, D., Johnell, O., & Wedel, H. (1996). Meta-analysis of how well measures of bone mineral density predict occurrence of osteoporotic fractures. BMJ, 312(7041), 1254-1259.
10. Richards, J. B., Rivadeneira, F., Inouye, M., Pastinen, T. M., Soranzo, N., Wilson, S. G., … & Valdes, A. M. (2008). Bone mineral density, osteoporosis, and osteoporotic fractures: a genome-wide association study. The Lancet, 371(9623), 1505-1512.
11. Vestergaard, P. (2007). Discrepancies in bone mineral density and fracture risk in patients with type 1 and type 2 diabetes—a meta-analysis. Osteoporosis International, 18(4), 427-444.