Expert Answer
How much vitamin D should you take per day?
Quick Answer
Dosing should be based on blood levels, not a fixed amount. Most experts recommend testing 25-hydroxy vitamin D and targeting 50-80 ng/mL. Common doses range from 1,000-5,000 IU/day of D3. Hyman recommends always pairing D3 with K2 for proper calcium metabolism.
Strong Consensus
on Vitamin D overall
What Researchers Say
Most data-driven advocate. Cites 40% lower dementia risk with D3 supplementation. Links deficiency to 5 years of accelerated biological aging.
Recommends D3 with K2 always. Targets 50-80 ng/mL blood levels. Warns that fortified foods use the less effective D2 form.
Takes 5,000 IU daily. Includes D3 in his personal stack. Doses based on blood monitoring. Most cautious about oversupplementation.
Includes D3 in his foundational protocol. Discusses UVB exposure as the natural source.
Includes vitamin D in his comprehensive Blueprint longevity protocol.
Detailed Answer
Unlike most supplements where a fixed dose is recommended, vitamin D dosing should be personalized based on your blood levels. The target range is 50-80 ng/mL on a 25-hydroxy vitamin D blood test.
Attia takes 5,000 IU of D3 daily, dosed based on blood monitoring. Patrick cites data showing 40% lower dementia risk and links deficiency to 5 years of accelerated biological aging.
Key protocol details: always use D3, not D2. Hyman recommends always pairing D3 with K2 to direct calcium to bones rather than arteries. Take with a fat-containing meal. Morning preferred — some evidence evening doses may interfere with melatonin.
Factors that increase your needs: darker skin, northern latitude, obesity, older age, limited sun exposure. Get a 25-hydroxy vitamin D blood test before supplementing and retest after 3 months.
Related Questions
Can you take too much vitamin D?
Yes. Hypervitaminosis D can cause hypercalcemia. Attia warns about this. Stay below 100 ng/mL and monitor blood levels.
Should you take vitamin D with vitamin K2?
Hyman strongly recommends this combination. K2 directs calcium to bones rather than arteries.
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