Everyone talks about boosting testosterone… but almost nobody understands the real lever behind it: Active Vitamin D. Not the supplement version in a softgel. Not the stuff pumped into processed milk. I’m talking about UVB-activated Vitamin D. The form your body actually uses to make hormones. When I doubled my testosterone naturally (450 → 900), this was one of the biggest players. UVB triggers a cascade in the skin that supplements simply cannot replicate. More active D = better hormone produc