Hi Amber, I think it’s important to note that the IOM regards 10,000 iu vitamin D3 daily as the safe upper limit for daily supplementation. 5,000 iu D3 daily is so very safe. However, I tend to think actual 25(OH)D blood level matters more than the daily dose. For example, I need to take more than 10,000 iu D3 daily to keep my 25(OH)D blood level at an optimal range. So, I test my blood regularly to ensure that I’m in balance.