Timing Protocol
What researchers say about when, how and with what to take vitamin d, and how strong the evidence is.
The verdict on Vitamin D overall
Leaning for
Vitamin D supplements are worth taking.
12 sources: 6 positive, 6 partly
Short answer
Take it with a meal that has fat for better absorption. Morning or midday is preferred; some evidence suggests evening doses can interfere with melatonin.
One verdict, worked out from every counted mention. One dot is one source: a researcher or a study. Tap a dot to see its receipt.
positive partly neutral negative Each researcher and each study counts once per claim, however often they come up.
Taking vitamin D with a fat-containing meal improves its absorption.
2 sources: 2 positive. Fewer than 3 sources so far.
Researchers say
2 positive
Mark Hyman, 2 mentions on this claim
Positive Video
on The Dr. Hyman Show, at 40:05 · positive
“the range I usually recommend is two to 5,000 units a day”
on The Dr. Hyman Show, at 26:13 · positive
“make sure you take it with a food that has fat because that's how you'll absorb it”
Roger Seheult, on Rangan Chatterjee's channel, at 28:01
Positive Video · Opinion
Open the tape at 28:01 →“unless you're eating something that has some fatty food in it uh it's not going to get well absorbed”
Studies show
No study counted yet.
Mark Hyman Video · positive · 2 mentions
on The Dr. Hyman Show, at 40:05 · positive · Opinion
“the range I usually recommend is two to 5,000 units a day”
on The Dr. Hyman Show, at 26:13 · positive · Opinion
“make sure you take it with a food that has fat because that's how you'll absorb it”
Roger Seheult, on Rangan Chatterjee's channel, at 28:01 Video · positive · Opinion
“unless you're eating something that has some fatty food in it uh it's not going to get well absorbed”
Built from every credited researcher and cited study on each claim.
Vitamin D supplements are worth taking.
Dr. William Li, 2 mentions on this claim
Positive Video
on Rangan Chatterjee's channel, at 55:25 · positive
“it's a lot easier to get your regular dose of daily vitamin d um by actually just having d3 supplements”
on Rangan Chatterjee's channel, at 58:54 · positive
“it's a lot easier to get your regular dose of daily vitamin d um by actually just having d3 supplements”
Andrew Huberman, on Huberman Lab, at 1:47:13
Positive Video · Opinion
Open the tape at 1:47:13 →“supplementing with anywhere from a th000 to 2,000 IU of vitamin D per day is probably safe for most people”
Dr Vonda Wright, on The Diary Of A CEO, at 1:17:26
Positive Video · Opinion
Open the tape at 1:17:26 →“it's something that everyone should supplement they should get their level checked”
Rhonda Patrick, 2 mentions on this claim
Positive Video
on FoundMyFitness, at 03:22 · positive
“there's a simple solution and that's why I like to talk about and that solution is actually taking a vitamin D supplement.”
on FoundMyFitness, at 42:57 · positive
“I currently supplement with 4,000 IU's per day and my levels are consistently 50 nanograms per”
Mark Hyman, 5 mentions on this claim
Positive Video
on The Dr. Hyman Show, at 40:05 · positive
“the range I usually recommend is two to 5,000 units a day”
on The Dr. Hyman Show, at 06:20 · positive
“it's important to make sure we we get adequate levels of vitamin D probably mostly through supplements”
on The Dr. Hyman Show, at 03:40 · positive
“for most people a good multi fish oil and vitamin D will do the trick”
on The Dr. Hyman Show, at 14:49 · positive
“your dose should be between a th000 to 5,000 units a day some people need 10,000”
on The Dr. Hyman Show, at 02:51 · positive
“i recommend at least a multi official vitamin d”
Andy Galpin, on The Diary Of A CEO, at 22:30
Positive Video · Opinion
Open the tape at 22:30 →“pretty good chance to be effective pretty low risk I'm okay with people really pushing vitamin D”
Elizabeth Boham, on The Dr. Hyman Show, at 12:23
Partly Video · Opinion
Open the tape at 12:23 →“they do better if we support with some supplementation for a period of time”
Dr. Kyle Gillett, on Huberman Lab, at 18:12
Partly Video · Opinion
Open the tape at 18:12 →“if you have deficient vitamin D, and you replace it, then you will optimize your testosterone.”
Roger Seheult, 2 mentions on this claim
Partly Video
on Rangan Chatterjee's channel, at 26:48 · partly
“in all of the patients that i am seeing in the hospital that are coming with cover 19 we're putting them on vitamin d supplementation”
on Rangan Chatterjee's channel, at 15:01 · partly
“supplementation with up to 4 000 international units a day probably would be beneficial especially if you're not able to get a lot of sunlight”
Chris Kresser, on The Dr. Hyman Show, at 15:01
Partly Video · Opinion
Open the tape at 15:01 →“so someone who's obese might need to take 10 000 IU of uh per day of vitamin D just to maintain a normal level yeah versus someone who's lean maybe 2000 IU would be sufficient”
Stuart Phillips, on FoundMyFitness, at 1:36:22
Partly Video · Opinion
Open the tape at 1:36:22 →“Definitely, in the winter months, vitamin D is, yep, absolutely.”
Gordon Lithgow, on FoundMyFitness, at 30:44
Partly Video · Opinion
Open the tape at 30:44 →“it's likely that if you are deficient, you really would benefit from coming up into a sensible range.”
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You know when to take Vitamin D. A free account opens the interaction warnings for your whole stack. Pro adds chat about your own situation, drawn from 3,700+ hours of recorded interviews with 380 researchers and doctors, plus 48,500+ research studies.
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