The 50,000 IU dose is a single dose, not a daily dose to be taken over some period of time. The half-life of vitamin D in the body is a few months, so a large

The 50,000 IU dose is a single dose, not a daily dose to be taken over some period of time. The half-life of vitamin D in the body is a few months, so a large single dose is effective for some time. A day in the sun is good for about 10,000 IU. (Source: http://www.ajcn.org/content/69/5/842.full http://www.ajcn.org/content/69/5/842.full )