Calcium supplements and bone health – everything you need to know to support strong bones
Quite often, once we hit the menopause years, we start thinking about supplements to either help with symptoms or to improve our health and prevent disease in the future. Bone health or osteoporosis prevention is one such health consequence of menopause, and many women decide to take calcium supplements to maintain strong bones, but, are they really needed?
What does the research say about calcium supplements
The research is conflicting as to whether calcium supplements are needed or not, and there are many questions around safe dosage requirements. There is no question that calcium is essential for bone health, especially through the menopause years and as women age.
Studies have shown that calcium supplements have had no effect on bone mineral density in populations where calcium intake from the diet has been sufficient, but there is evidence that if there isn’t enough dietary calcium, supplementation is beneficial.
Where the conflict arises though, is that calcium supplementation gives no benefit in preventing fracture risk for the hip or spine even though it is often the first type of management in osteoporosis prevention. Calcium supplementation has also been linked to heart disease, while the evidence for digestive side effects and the formation of kidney stones is inconsistent.
So let’s break this down a little…….
The role of calcium in the body
Calcium is the most abundant mineral in the body. Ninety nine percent of calcium is stored in our bones, and just one percent circulates in our blood, performing many important roles in the proper functioning of nerves, muscles and the heart, and it is needed for cell signalling, blood clotting and the maintenance and strength of bones.
Calcium in our blood is tightly regulated by a series of reactions that involve the parathyroid gland (releases parathyroid hormone, or PTH), thyroid gland (releases calcitonin, a hormone) and the kidneys (releases calcitriol, the hormonal form of Vitamin D) and their associated hormones. Blood calcium must always be maintained at one percent, and the balance is maintained by the actions of the hormones PTH, calcitonin and calcitriol, either by releasing calcium from the bones into the bloodstream, or not.
We know that in the menopause years, as oestrogen fluctuates and declines, that the bone remodelling cycle can be negatively affected, resulting in more bone breaking down than building up – resulting in bone loss. However, calcium balance does not reflect bone balance, which may be why studies show that increased calcium supplementation has no effect at all on fracture risk of the hip or spine.
The heart and calcium supplementation
We also know from studies that calcium supplements are not processed in the body in the same way as calcium from our diet. There is evidence that calcium supplements consumed at higher daily doses (1000mg/day or more) can increase the incidence of heart damage and plaque build up in the arteries.
One randomised, placebo controlled trial that included 1471 healthy post menopausal women with a 5 year follow up showed 1000mg/day of supplemental calcium increased the incidence of cardiovascular events. Another study that included more than 34000 post menopausal women, found that when calcium supplementation was stopped, the incidence of cardiovascular effects also stopped. Other studies have shown that calcium supplements taken by older people don’t make it to the skeleton at all, and are either excreted in faeces or urine, or deposited elsewhere in the body.
The digestive system and calcium supplementation
Two types of calcium supplements, calcium carbonate and calcium citrate have been shown to increase digestive upset. Calcium carbonate is often associated with constipation, bloating and flatulence, and calcium citrate is often associated with constipation, severe diarrhea and abdominal pain. Calcium carbonate should be taken with a meal, as it dissolves well in the acidic environment of the stomach, and calcium citrate can be taken anytime of the day as it doesn’t need the acidic environment to dissolve. More research is needed in relation to calcium supplements and the effects on the digestive system.
The kidneys and calcium supplementation
There is a possibility that calcium supplementation could cause kidney stones, but the evidence is not consistent. One study in 2006 included 36282 post menopausal women aged 50-70 years with a 7 year follow up, and consisted of 2 groups, either receiving calcium with vitamin D or a placebo. There was a 17% increased risk of developing kidney stones in the group that received the calcium and vitamin D compared to the placebo group. This result is inconclusive, and generally speaking, kidney stones don’t normally form in a healthy kidney, there are usually other contributing factors.
So…..the question is, to supplement or not supplement?
There is no question that getting your daily recommended intake of calcium through your diet is the safest way to avoid issues with your heart and possibly digestive system and kidneys, in fact dietary calcium intake is protective. There is growing evidence that taking calcium supplements may be more harmful to your health, while many studies have shown that calcium supplementation has no effect in preventing fractures in the future.
The body can’t process more than 500mg at a time (that includes dietary and supplements), so if you are taking more than that, it is likely that your body is dealing with excess calcium.
A conservative approach to taking calcium supplements is recommended. Consuming small amounts of calcium rich foods throughout the day with other foods should allow for the recommended intakes to be reached. If you are unable to reach the recommended intakes through diet, then calcium supplementation should be used. It is always recommended that we consume dietary calcium first and foremost, and top up with calcium supplements if needed. You should always consult with your doctor before taking supplements, and have the relevant tests done to see that they are actually needed. Calcium is definitely one of those supplements that you need to be informed about before deciding to take it.
I hope this article shed some light for you about calcium supplements and the possible adverse health effects that can occur if you are taking high amounts over a long period of time. This article is for information purposes only. Always consult your doctor before taking supplements to make sure that it is safe for you.
References:
- Anderson, JB et al, Calcium Intake from Diet and Supplements and the Risk of Coronary Artery Calcification and it’s Progression Among Older Adults: 10-Year Follow-up of the Multi-Ethnic Study of Atherosclerosis (MESA), J Am Heart Assoc, Vol 5, No 10, 11 October 2016
https://www.ahajournals.org/doi/full/10.1161/jaha.116.003815
- Chan Soo Shin, Kyoung Min Kim, The Risks and Benefits of Calcium Supplementation, Endocrinol Metab (Seoul), 2015 March;30(1):27-34
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4384676/
- Cleveland Clinic, Osteoporosis: Prevention with Calcium Treatment
https://my.clevelandclinic.org/health/articles/15049-osteoporosis-prevention-with-calcium-treatment
- John Hopkins Medicine, Health, Calcium Supplements: should you take them?
- John Hopkins Medicine, Calcium Supplements May Damage the Heart
https://www.hopkinsmedicine.org/news/media/releases/calcium_supplements_may_damage_the_heart
- Li K et al, The good, the bad, and the ugly of calcium supplementation: a review of calcium intake on human health, Clin Interv Aging, 2018; 13:2443-2452
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6276611/
- Reid IR, Bristow SM, Bolland MJ, Calcium Supplements: benefits and risks, J Int Med, Vol 278 Issue 4 October 2015
https://onlinelibrary.wiley.com/doi/full/10.1111/joim.12394
