04/19/2026
A-Z of Brain Health Supplements: D for Vitamin D3.
Vitamin D is technically more of a hormone than a vitamin. Your skin absorbs UVB radiation from the sun to eventually create calcitriol, the active form of vitamin D, but you can also get it from foods and supplements. Vitamin D plays a major role in key brain areas responsible for mood, memory, and even dopamine function.
Living in Canada, up to 50% of people are vitamin D deficient, especially during the winter months, so supplementing with vitamin D can typically be a smart idea.
1000-4000 IU (International Units) of vitamin D3 per day seems to be the dose range to bring your vitamin D levels into the correct range. Because vitamin D is fat soluble, taking vitamin D with a high-fat meal can also benefit absorption.
One of the only supplements I think almost everybody could benefit from, I give vitamin D3 an A+