Which Calcium is best?
In the last Clinicians Corner, we discussed Vitamin-D supplementation. Although Vitamin-D is helpful in immune system functioning, its primary role is in maintaining calcium regulation in the body. Vitamin-D is necessary for calcium absorption to occur out of our gastrointestinal tract.
Many of our patients, because they are elderly or take acid suppressing drugs, have limited stomach acid. Calcium carbonate, which is made from oyster shells, requires acid for dissolution and absorption. With many of our patients taking acid suppressing therapy, Calcium citrate which does not require acid for dissolution, is a better option for this group.
Calcium carbonate: (Os-Cal-500)
· Contains 40% Calcium (500mg Calcium per tablet)
· Should be taken with a meal. Optimal absorption occurs in the presence of gastric acid.
· May cause constipation, divided dosing and adequate fluids should alleviate its occurrence.
· Must divide doses. Approximately 500mg can be absorbed at a single time.
· Keep in mind that “Tums®” antacid is calcium carbonate in a chewable form. It is a lot less expensive than the chewable calcium supplements. Generic Tums® Ultra is 1000mg of Calcium carbonate, that releases 400mg calcium. Ask your Nickman’s pharmacist to help you save money!
Calcium Citrate (Citrical®)
· Contains 24% calcium (200mg Calcium per tablet)
· May be taken with or without meals. Does not require stomach acid for absorption.
· Best choice for elderly with reduced gastric acid.
· Best choice for patients taking acid suppressing drugs like Prilosec and Pepcid.
· Works best for patients complaining of stomach upset.
· Best choice for patients who have had gastric bypass surgery.
Drug Interactions with Calcium—ask your Nickman’s pharmacist!
· Tetracyclines, fluoroquinolones—decreased absorption of antibiotic. Separate doses by at least 2 hours
· Thyroid supplements & some osteoporosis drugs—decreased efficacy. Separate dose by 4 hours.
· Corticosteroids decrease absorption of calcium, and over time can lead to osteoporosis.
· Thiazide diuretics like HCTZ increase urinary calcium reabsorption. Studies have shown fewer fractures on patients on thiazide diuretics. If diuresis is needed, a thiazide would be of good choice. Loop diuretics like Lasix increase the excretion of calcium.
If you have special conditions, or just want to save money on your supplements, always ask your Nickman’s pharmacist for advice.