How much vitamin D should I take?

Recommended vitamin D intake varies by age, health status, sun exposure, and where you live. General guidelines can help, but your needs may differ.

General recommendations

Many health authorities suggest around 600–800 IU (15–20 mcg) per day for adults to support bone health. Older adults and people with limited sun exposure or darker skin may need more. Some experts suggest 1000–2000 IU daily for maintenance when blood levels are adequate. Higher doses are sometimes used short-term under medical supervision if deficiency is confirmed.

Testing and individual needs

A blood test (25-hydroxyvitamin D) can show whether you are deficient, sufficient, or high. Deficiency is often defined as below 20 ng/mL (50 nmol/L); optimal ranges are often cited as roughly 30–50 ng/mL. If you are deficient, your doctor may recommend a higher dose for a period, then a maintenance dose.

Safety

Very high doses taken long-term can lead to excessive calcium in the blood and other risks. Staying within recommended upper limits (e.g. 4000 IU per day for adults unless advised otherwise) and having levels checked when appropriate helps support safe use. This is not medical advice; consult a healthcare provider for dosing tailored to you.