Do vitamin D supplements have side effects?

Vitamin D has very few side effects when used as directed.

If you take very large doses of vitamin D, you could develop vitamin D toxicity. While this is uncommon, symptoms include nausea, vomiting, poor appetite, constipation, weakness, weight loss and kidney damage. 

Be careful if you are taking a supplement that contains other active ingredients. If you take more than the recommended dose of the supplement, you could overdose on these other active ingredients. Or you could double dose by taking another medicine with the same active ingredients.

Read more about the active ingredients in vitamin D supplements.

Remember that vitamin supplements are medicines and, like all medicines, they have potential risks and benefits. Speak to your doctor or pharmacist about supplements containing vitamin D.

To speak to a health professional over the phone, call NPS Medicine Line on 1300 MEDICINE (1300 633 424 ) Mon–Fri, 9am–5pm AEST. Calls will be answered by healthdirect Australia.

If you’ve had, or think you’ve had, more than the recommended dose of a vitamin D supplement, call the Poisons Information Centre on 13 11 26.

Many supplements are combined with calcium, which can be beneficial, but you should be careful of calcium toxicity. Avoid taking more than 600–1000 mg of calcium per day unless directed by your doctor. Signs of calcium toxicity include confusion, disorientation, and problems with heart rhythm.

Download our 'Vitamin D tests and deficiency' fact sheet to find out if you are at risk of deficiency, how to improve your vitamin D levels, and whether you need a vitamin D test.

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