Is 5000 IU of vitamin D too much?

5,000 IU (125 micrograms) of vitamin D is above the adult upper limit of 4,000 IU (100 micrograms) a day. That is about 8.3 times the adult RDA of 600 IU (15 micrograms). Doctors sometimes advise more for a set time, so check with yours before taking this much.

Checked 28 September 2026 · Sources: NIH Office of Dietary Supplements fact sheet and NHS vitamins and minerals guidance · Adults onlyUS: Above the upper limitUK: Above NHS guidance

General information, not medical advice. Check with a doctor or pharmacist before taking a supplement, especially if you are pregnant or breastfeeding, take any medicine, or are under 18.

In the UK

5,000 IU (125 micrograms) of vitamin D is above the NHS guidance of 100 micrograms (4,000 IU) a day. In the UK, adults need 10 micrograms (400 IU) a day. Doctors sometimes advise more for a set time, so check with yours before taking this much.

The figures

US (NIH)UK (NHS)
Amount checked5,000 IU (125 mcg)
AnswerAbove the upper limitAbove NHS guidance
Compared with4,000 IU (100 micrograms) a day100 micrograms (4,000 IU) a day
Share of the limit125% of the limit125% of the limit
Adults need600 IU (15 micrograms) a day, or 800 IU (20 micrograms) over age 7010 micrograms (400 IU) a day

Good to know

Quick answers

Is 5000 IU of vitamin D too much?
5,000 IU (125 micrograms) of vitamin D is above the adult upper limit of 4,000 IU (100 micrograms) a day. That is about 8.3 times the adult RDA of 600 IU (15 micrograms). Doctors sometimes advise more for a set time, so check with yours before taking this much.
What does the NHS say about 5,000 IU of vitamin D?
5,000 IU (125 micrograms) of vitamin D is above the NHS guidance of 100 micrograms (4,000 IU) a day. In the UK, adults need 10 micrograms (400 IU) a day. Doctors sometimes advise more for a set time, so check with yours before taking this much.
What is the upper limit for vitamin D?
US: 4,000 IU (100 micrograms) a day. UK (NHS): 100 micrograms (4,000 IU) a day.

Sources

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