If you choose to take vitamin D supplements, 10μg a day will be enough for most people.
People who take supplements are advised not to take more than 100μg of vitamin D a day, as it could be harmful (100 micrograms is equal to 0.1 milligrams).
This applies to adults, including pregnant and breastfeeding women and the elderly, and children aged 11 to 17. Some people have medical conditions that mean they may not be able to take as much vitamin D safely.
If in doubt, you should talk to your doctor. If your doctor has recommended you take a different amount of vitamin D, you should follow their advice.
Source: https://www.nhs.uk/live-well/healthy-body/how-to-get-vitamin-d-from-sunlight/