I've been wondering if the recommended levels might be a bit high, & how they were actually determined.
I sunbathe during the Summer months to get my D. Had levels checked at the end of last Summer and was shocked when I pulled a 29 flagged as LOW. This was after sunbathing at solar noon (around 1:PM daylight saving) once every few weeks for an hour to an hour & half at a time. I also wear shorts & T shirt most days and get plenty of time outside during the day.
I supplement 2000 IU/day during the Winter when you can't get D from the sun. Checked it again this Spring, & was down to 23 (LOW). It seems somehow unnatural to think regular sunbathing during the Summer & regular mid-level supplementation during the Winter might still result in a substantial deficiency.
I'm a bit reticent to start frying myself every week or upping my supp dose to 5K/day as I've read too much D may be associated with calcifications. Morley Robbins (the magnesium man) opines too much D can disable functionality of Vitamin-A, much like too much zinc can push copper into obscurity. Robbins also opined the competitive issues between too much D hampering A might lower ceruloplasmin, buggering copper and iron transport.
I'm curious how Mother Nature could have screwed up so badly by evolving an organism that would be chronically deficient without continuous high level supplementation. I know man used to spend a lot more time outdoors, but I expect even a neanderthal would have enough sense to avoid being out in the mid-day sun too long.
Edited by Dorian Grey, 21 August 2018 - 03:30 AM.