AS A PHARMACIST, you will hear more debate about whether calcium supplements are safe. New evidence suggests these supplements are linked to dementia. But this is mainly in elderly women who've had a stroke and does NOT prove that calcium supplements cause dementia. Plus previous concerns about calcium supplements and cardiovascular (CV) risk may be waning. A recent analysis suggests calcium intake that doesn't exceed the recommended upper limit is not associated with a higher cardiovascular (CV) risk. Getting too much calcium from foods alone is rare.
Recommend 1000 mg/day of elemental calcium for women up to age 50 and men up to 70 and 1200 mg/day for older adults. But warn not to exceed the upper limit of 2500 mg/day for adults up to age 50 or 2000 mg/day for those over 50 to avoid hypercalcemia and other problems. Calcium supplements (calcium carbonate, calcium acetate and calcium citrate).
Calcium Carbonate (Calcimate 500 mg) is 40% elemental calcium. So, one capsule of Calcimate 500 mg will give 200 mg elemental calcium. Calcium carbonate dissolves best in an acidic environment. Its absorption is significantly impaired by acid-reducing drugs such as proton pump inhibitors, or in the elderly. Calcium Acetate (Marcal 700 mg) will give 177 mg elemental calcium. Calcium Citrate is only 21% elemental calcium, but compared to calcium carbonate, it is better absorbed. This is likely because it dissolves better than calcium carbonate in the high-pH environment of the ileum, the main site of calcium absorption. For example, Cal-Mag 665 mg will give 140 mg elemental calcium (contain also magnesium supplements), Calcium Pharco 950 mg will give 200 mg elemental calcium.
Encourage patients to get most or all of their calcium from food and to use supplements to fill in any gaps. To calculate dietary calcium intake, count 300 mg/day from all nondairy foods, plus 300 mg per cup of calcium-rich foods (milk, yogurt, fortified juice, etc). Steps to estimate your calcium intake is available at: https://www.nof.org/patients/treatment/calciumvitamin-d/steps-to-estimate-your-calcium-intake. CALCIUM CALCULATOR is available at: https://www.osteoporosis.foundation/educational-hub/topic/calcium-calculator.
IF A SUPPLEMENT IS NEEDED, suggest calcium carbonate (Calcimate) for the most calcium per tab and generally lower cost. Lean toward calcium citrate (Cal-Mag) for patients on acid blockers (like PPI) or the elderly, it may be better absorbed. Advise dividing doses over 500 mg to improve absorption.
REFERENCES
Kopecky, S.L., Bauer, D.C., Gulati, and others (2016). Lack of Evidence Linking Calcium With or Without Vitamin D Supplementation to Cardiovascular Disease in Generally Healthy Adults: A Clinical Guideline From the National Osteoporosis Foundation and the American Society for Preventive Cardiology. Annals of Internal Medicine, 165(12), p.867. Available at: https://www.acpjournals.org/doi/10.7326/M16-1743
Kern, J., Kern, S., and others (2016). Calcium supplementation and risk of dementia in women with cerebrovascular disease. Neurology, [online] 87(16), pp.1674–1680. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5085079