Endocrinology Metabolism

Calcium in osteoporotic patients

Are you sure the Patient has a Need for Calcium for Osteoporosis?

Management and Treatment of the Disease

Should I prescribe calcium for my patient with osteoporosis? If so, how much?

Need for calcium: Modern studies of osteoporosis treatment have included calcium (and vitamin D) with the pharmacologic treatment. There is a little evidence that calcium plus vitamin D has a minor salutary effect on fracture risk. So, in general calcium is good for bones.

How much? The Institute of Medicine (IOM) recommended that most adults ingest 1000-1200 mg of calcium daily. This is the total elemental calcium from diet and supplements if necessary. The American diet has more calcium than thought previously, probably because more foods are fortified with calcium. Nonetheless it is still somewhat difficult to obtain adequate calcium without ingesting dairy foods. For those patients who are lactose intolerant, lactase tablets are readily available.

Is more calcium better? No. The gut can only absorb about 500 mg of elemental at any one time. Higher than 1200 mg of calcium daily may increase the risk of kidney stones, although in some cases a really low oral calcium intake can actually lead to more stones. So, we suggest following the IOM guidelines on calcium intake.

My patient with osteoporosis likes coral calcium. Is this better? What about chocolate calcium chews?

Some more exotic calcium preparations may contain lead and/or arsenic. Therefore, plain calcium carbonate or calcium citrate should be used from a reliable source. Calcium carbonate should be taken with meals because stomach acid is needed for absorption. The chocolate chews are generally okay, but remember that more is not necessarily better.

Is calcium safe for that osteoporosis patient with declining renal function?

In patients with end-stage renal disease (CKD 5 on dialysis), calcium-containing phosphate binders were associated with more coronary artery calcification than sevelamer, which does not contain calcium. Extrapolating to those with declining renal function with aging (and with increasing fracture risk with aging) is difficult. More study is needed to determine if those osteoporosis patients with CKD 3 or 4 should ingest lower amounts of calcium than those with more normal renal function, although no problems were seen in most osteoporosis studies that included subjects with CKD 3 or 4.

If there is evidence of coronary calcification in renal failure patients taking calcium, what about the reports that calcium supplementation increases cardiovascular risk in all adults?

There is some evidence to support and discount a deleterious effect of calcium ingestion on blood vessels. It is not easy to find an answer that will satisfy both sides of this debate. For now, we suggest following the IOM recommendations that most adults need 1000 to 1200 mg of elemental calcium daily.

The most recent reviews of calcium and cardiovascular risk have failed to show a deleterious effect. Thus, most experts agree with the IOM plan.

Is magnesium helpful for osteoporosis?

The role of magnesium in osteoporosis is not established. It is interesting that a drug class, the proton pump inhibitors, is associated with both increased fracture risk and hypomagnesemia. Nonetheless, a connection between the two outcomes has not been established.

The cathartic effect of magnesium may neutralize the constipating effect of calcium. Thus, taking both calcium and magnesium - often available together - is appealing.

If the patient has a co-existing disease or medication use, how will that effect your treatment decision?

Tell the user when to switch if it appears the treatment is not proving effective and what to consider switching to.

What’s the Evidence?/References

Ross, A.C., Manson, J.E., Abrams, S.A.. "The 2011 report on dietary reference intakes for calcium and vitamin D from the Institute of Medicine: what clinicians need to know". J Clin Endocrinol. vol. 96. 2011. pp. 53-58.

(The IOM report concludes that about 1200 mg of elemental calcium daily is appropriate for most adults.)

Kakuta, T., Tanaka, R., Hvodo, T.. "Effect of sevelamer and calcium-based phosphate binders on coronary artery calcification and accumulation of circulating advanced glycation end products in hemodialysis patients". Am J Kidney Dis. vol. 57. 2011. pp. 422-431.

(For patients with end-stage renal disease on hemodialysis, using sevelamer (which does not contain calcium) was associated with lower coronary calcium deposits than using calcium-containing phosphate binders. The applicability to patients with lesser degrees of kidney disease has not been established.)

Reed, I.R., Bolland, M.J., Avenell, A.. "Cardiovascular effects of calcium supplementation". Osteoporos Int. vol. 22. 2011. pp. 1649-1658.

(This paper reviews the evidence that calcium supplements have detrimental effects on the cardiovascular system.)

Lewis, J.R., Calver, J., Zhu, K.. "Calcium supplementation and the risks of atherosclerotic vascular disease in older women: results of a 5-year RCT and a 4.5-year follow-up". J Bone Miner Res. vol. 26. 2011. pp. 35-41.

(In this randomized trial with pre-specified and adjudicated cardiovascular endpoints, there was no evidence of detrimental effects of calcium supplements.)

Weaver, C.M.. "Calcium supplementation: is protecting against osteoporosis counter to protecting against cardiovascular disease?". Curr Osteoporos Rep. vol. 12. 2014. pp. 211-218.

(This is a recent review of the evidence regarding calcium supplements and cardiovascular disease. Overall the case for harm is not strong, but the author concurs with the IOM recommendations.)

Bockman, R.S., Zapalowski, C., Kiel, D.P. "Commentary on calcium supplements and cardiovascular events". J Clin Densitom. vol. 15. 2012. pp. 130-134.

(This commentary reviews the controversy on potential adverse cardiovascular effects of calcium supplements and highlights some of the difficulties in interpreting the literature.)

Weaver, C.M., Alexander, D.D., Boushey, C.J.. "Calcium plus vitamin D supplementation and the risks of fractures: an updated meta-analysis from the National Osteoporosis Foundation". Osteoporos Int. vol. 27. 2016. pp. 367-376.

(In this excellent review, a modest effect of calcium and vitamin D to diminish fracture risk is supported by the meta-analysis.)

Fernandez-Fernandez, F.J, Sesma, P., Cainzos-Romero, T.. "Intermittent use of pantoprazole and famotidine in severe hypomagnesemia due to omeprazole". Medicine. vol. 68. 2010. pp. 329-330.

(This interesting case report illustrates how some clever physicians managed the problem of very low serum magnesium with out of control gastro-esophageal reflux.)
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