Your skin releases around 10,000 IU if you spend an hour outside in full sun in the summer. So that, at least, should be quite safe. This article from the Mayo

Your skin releases around 10,000 IU if you spend an hour outside in full sun in the summer. So that, at least, should be quite safe. This article from the Mayo Clinic argues that vitamin D toxicity has been vastly overstated. [1] [1] https://www.mayoclinicproceedings.org/article/S0025-6196%2815%2900244-X/fulltext https://www.mayoclinicproceedings.org/article/S0025-6196%281...