What is vitamin D supplement used for?

Vitamin D helps the intestine absorb calcium, which the body uses to maintain bones and muscles. A clinician may recommend a supplement when blood results, diet, limited sun exposure, pregnancy planning, pregnancy care, or another health factor suggests that intake needs support. The right product and dose depend on your age, health, diet, and other supplements.

Use the product exactly as directed and tell your clinician about kidney disease, high calcium, sarcoidosis, or medicines and supplements you take. Check the label before combining products, since more than one supplement may contain vitamin D. Keep the container away from children, and ask whether a blood test or review is needed.

Stop and seek medical advice if you develop persistent nausea, vomiting, unusual thirst, frequent urination, confusion, or marked weakness after taking a supplement. These symptoms can have many causes, but may need prompt assessment for excess calcium or another problem.

Ask whether you need testing, what dose and formulation suit you, how long to take it, and whether it should be taken with food. If you are pregnant, breastfeeding, or preparing for pregnancy, ask how vitamin D fits with your antenatal or preconception plan.