Is 5000 IU of vitamin D too much?

"Too much" depends on your starting level, not on the number on the bottle. The experts work from a range — roughly 1,000-5,000 IU of D3 daily — and set the dose by a blood test rather than a fixed prescription. The relevant safety guardrail: 4,000 IU/day is generally considered the upper limit for adults without medical supervision, because vitamin D is fat-soluble and accumulates. So 5,000 IU isn't automatically too much, but it's a dose worth confirming against your own labs — especially since people with higher body fat sequester vitamin D and may genuinely need more.

The split on our panel is about how aggressively to push levels. Patrick and Hyman are the advocates: most people are suboptimal (Hyman targets 50-80 ng/mL), and Patrick cites a 12,000-person study where supplementation tracked a 40% lower dementia risk over a decade. Attia is the brake: he warns about hypervitaminosis D (which can cause hypercalcemia), notes the blood assays themselves are unreliable lab-to-lab, and makes the contrarian point that some of vitamin D's benefits may actually come from the outdoor, active lifestyle needed to raise it naturally — not the supplement. He still takes D3, but doses it to blood levels.

Practical path: get a 25-hydroxy vitamin D test before settling on a dose, retest after about three months, and adjust. If you do take higher doses, the cofactors matter — Hyman pairs D3 with K2 (so calcium goes to bone, not arteries) and magnesium (required to convert D into its active form). The honest takeaway: 5,000 IU is fine for many deficient people, overkill for some, and only your bloodwork tells you which you are.