How often should you test with the Vitamin D test?

We recommend to test yourself every 120 days to see your level of Vitamin D.
The season etc. can make the levels change, showing that you sometimes need or do not need extra Vitamin D.

If you are interested in following your Vitamin D levels more often, you can test yourself every 30 days, but not more often than that.
(It will not show that much of a difference if you test more often)