See how much vitamin D women need, and a sensible supplement amount when sun is limited, based on the same evidence as our vitamin D guide. Nothing is stored.

Suggested supplement

1000–2000 IU / day (25–50 mcg)

A reasonable, safe amount when you get little sun.

Vitamin D works with calcium for bone health, so many women pair the two.

Figures follow our vitamin D guide: most adults need about 600 IU (15 mcg) a day, rising to 800 IU (20 mcg) over 70, with 1000–2000 IU a sensible supplement when sun is limited. Keep below 4000 IU a day unless a doctor advises more. A blood test and dosing guide tells you where you stand. This tool is information, not medical advice.

How it works

Enter your age and how much sun you get to see the vitamin D women need and a sensible supplement amount.

The formula and sources

It uses 600 IU (15 mcg) a day for most adults and 800 IU (20 mcg) from age 70, and suggests 1,000 to 2,000 IU from a supplement when sun is limited, staying under the 4,000 IU upper limit. These figures come from our vitamin D guide.

Assumptions

You are a generally healthy adult.
The figure combines food, sun, and supplements.

Limitations

This is intake guidance, not a substitute for a blood test. The only way to know your level is a 25(OH)D test, which matters before taking higher doses.

When to see a doctor

Ask for a blood test before starting a high-dose supplement, especially if you have a condition affecting calcium or vitamin D.

Primary sources

National Academies, Dietary Reference Intakes for Calcium and Vitamin D (2011). The report of record for the daily intakes and the upper limit used here.
Nutrients, 2024. Supports a common supplemental dose of 2,000 IU a day, a blood level at or above 30 ng/mL, and an upper limit of 4,000 IU a day.

Calculator version 1.0. Figures and formula last checked 27 July 2026 against the sources above. This tool gives general information and does not replace advice from your own doctor.

Frequently asked questions

How much vitamin D should a woman take?

Most adults need 600 IU (15 mcg) a day, rising to 800 IU (20 mcg) from age 70. When sun is limited, 1,000 to 2,000 IU from a supplement is sensible, staying under the 4,000 IU upper limit.

Do I need a vitamin D supplement?

Many women do in autumn and winter, or year-round with little sun exposure, darker skin, or mostly covered skin. A blood test confirms it.

Can I get enough vitamin D from food?

Food alone rarely covers it. Oily fish, eggs and fortified foods help, but sun and supplements do most of the work.

How do I find out my vitamin D level?

A 25(OH)D blood test is the measure, and it matters before taking higher doses. See our vitamin D guide.

Vitamin D Calculator: How Much Women Need