Can I just get enough Vitamin D from sun exposure instead of supplementation?Updated 21 days ago

Possibly — but sun exposure is a far less reliable Vitamin D source than most people assume. UVB rays, which trigger Vitamin D synthesis in the skin, are only present at sufficient angles for synthesis during certain hours of the day and certain times of year depending on your latitude. Sunscreen, clothing, glass, air pollution, and skin tone all reduce synthesis further. And even in ideal conditions, the body caps natural production at a point — you can't synthesize your way to optimal levels the way many people believe. 

The only way to know whether your sun exposure is translating into adequate Vitamin D status is to test. Bloodwork removes the guesswork.