The best way to approach it, I think, is to take a consistent amount daily. Then in a month have your blood tested to check for levels of vitamin d. Then adjust. Once you find your dose you don’t have to constantly check unless something changes.

The fat soluble vitamins can build up in your body. They are vitamin A, D, E, and K. These can be a problem if you take too much.

The water soluble vitamins like C and B are excreted in the urine if you take too much as long as your kidneys work properly.