I recently got a broad panel of tests done, and found out I was Vitamin D deficient. This was a big surprise to me because I live in the high desert of central oregon, which gets lots of sun even in the winter. I am very active and outside everyday. It is cold however, so my arms are always covered. We are 45 degrees north of the equator.
I was at 20 ng/mL which is considered deficient. 3 weeks of 5,000 IU a day supplementation (162lbs, fit, active male) brought me up to 31 ng/mL, which is just barely up from deficient. I upped to 10,000 IU a day for 1 week, dropped back to 5,000 IU a day, and will test again in two weeks. Everyone is different, but hopefully this gives some helpful numbers for anyone considering supplementing, and whether or not the paltry 1,000 IU commonly advised is adequate for people living at a higher latitude in the winter.
I was at 20 ng/mL which is considered deficient. 3 weeks of 5,000 IU a day supplementation (162lbs, fit, active male) brought me up to 31 ng/mL, which is just barely up from deficient. I upped to 10,000 IU a day for 1 week, dropped back to 5,000 IU a day, and will test again in two weeks. Everyone is different, but hopefully this gives some helpful numbers for anyone considering supplementing, and whether or not the paltry 1,000 IU commonly advised is adequate for people living at a higher latitude in the winter.