Quite long but a great overview of a crucial vitamin/hormone many of us are very deficient in. I stopped using deodorant soaps in the 70s after learning they kill skin bacteria crucial to our making our own D3 using sunlight. A friend in Albuquerque with scary bone and other issues at 74 and who is RARELY outdoors inspired me to re-look into it. Per my suggestion she ordered D3 caplets, 1000 IU, at a great price and they arrived today. Us gardeners should be fine...if we have a healthy skin biome, just 15 minutes in the sun with a lot of skin exposed can give us 20,000 IU!