How ironic, D3 & zinc are the only 2 supplements I take. Vitamin D has been a game changer for me. In this region of the country we lose significant sun exposure from roughly November until April. For decades my body was a mess come March, last year I started on the D3 (10.000 IU) & 50mg zinc daily in the fall and it did me worlds of good. I ratcheted the D back to 5000 IU daily once spring came back. Most people in general are sorely lacking D and it’s a crucial vitamin.