Pharmacist warning: what vitamin D users should actually know
The headline “pharmacists warn everyone taking vitamin D” is too dramatic. Vitamin D is important for bone and muscle health, and supplements are appropriate for some people. The main concern is taking unnecessarily high doses for long periods. (ods.od.nih.gov
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5 things to watch for
Don’t automatically take high doses. For adults, the general upper limit is 4,000 IU (100 mcg) per day from all sources unless a clinician has prescribed more to treat a deficiency. (ods.od.nih.gov
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Too much can raise calcium levels. Vitamin D toxicity can cause nausea, vomiting, weakness, confusion, excessive thirst/urination, and kidney stones. Severe toxicity can damage the kidneys and heart. (ods.od.nih.gov
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Check your other supplements. Multivitamins and calcium supplements may already contain vitamin D, so adding another product can unintentionally push your total intake too high. (ods.od.nih.gov
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Some medicines interact with vitamin D. Particular caution is warranted with digoxin, thiazide diuretics, certain seizure medicines, steroids, orlistat, and cholestyramine. (nhs.uk
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Kidney problems deserve extra caution. Excess vitamin D can contribute to high calcium and kidney stones or kidney damage. People with kidney disease should discuss supplementation with their clinician. (nhs.uk
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Bottom line: Don’t be afraid of vitamin D—but don’t assume that a larger dose is better. If you’re taking vitamin D, tell your pharmacist or doctor the exact dose (IU/mcg), how often you take it, and what other medicines/supplements you use. They can determine whether the dose is appropriate.
