It probably depends if you’re getting enough. The best way would be if your doctor tests your levels. My doctor initially prescribed me to take like a 50,000 IU dose once a week with dinner or something like that, but I found it hard to remember. I asked about switching to something daily and took an over-the-counter pill every day, which became a routine and harder to miss. After another test we doubled it so I take two pills every day and now an in a better range. But there were months in between the tests, so I think it takes time to really have an impact.