Vitamin D

Dr. Andrew Huberman Recommends as Foundational

Huberman covers vitamin D extensively through guest experts on his show, particularly Rhonda Patrick and Roger Seheult. He includes vitamin D in his foundational supplementation protocol and has dedicated episodes to sunlight's role in health — covering UVB exposure for vitamin D production, immune function, hormonal effects, and circadian rhythm. He also discusses vitamin D's role in preventing colds and flu, noting it may offer protection especially for those with low levels. His practical recommendation is to get morning sunlight exposure and supplement D3 as part of a foundational protocol.

4 more clips

• 06:13 · Essentials: Micronutrients for Health & Longevity | Dr. Rhonda Patrick (Guest: Rhonda Patrick)
• 35:45 · Micronutrients for Health & Longevity | Dr. Rhonda Patrick (Guest: Rhonda Patrick)
• 20:00 · How to Prevent & Treat Colds & Flu
• 01:52:54 · Female-Specific Exercise & Nutrition for Health, Performance & Longevity | Dr. Stacy Sims (Guest: Stacy Sims)

Dr. Peter Attia Cautious — Lifestyle Over Supplement

Attia provides the most cautious perspective on vitamin D among the five experts. While he acknowledges its importance for bone health — grouping it with calcium and magnesium as 'the big three' — he raises a provocative argument: that health benefits attributed to high vitamin D levels may actually stem from the active, outdoor lifestyle required to achieve them naturally. He warns about hypervitaminosis D, notes that blood test assays are unreliable, and emphasizes dietary intake and safe sun exposure over supplementation. In his supplement list, he does include D3 but with the caveat that dose should be guided by blood levels.

…put yourself in a bubble with zero UV exposure and you know only get your vitamin D from supplemental capsules um I don't think you're healthy a lot of the epidemiology that suggests the significant benefits of vitamin D which by the way are often not replicated in studies although I would argue those studies are often woefully done some have speculated that it might be less the vitamin D the higher vitamin D levels in those individuals and more what they're doing to achieve high levels of vitamin D if they're doing it without supplementation namely just being outside and being active you ask me what do I do with our patients when…

▶ 00:36 · Balancing the benefits and risks of sun exposure

3 more clips

• 05:36 · How to optimize your children's bone health through diet, sunlight exposure, and physical activity
• 86:41 · Navigating bone health: early life influences & strategies for improvement & injury prevention
• 00:00 · Peter Attia's Supplement List

Dr. Rhonda Patrick Strongly Recommends

Patrick is the strongest and most data-driven advocate for vitamin D supplementation. She presents it as a steroid hormone regulating over 1,000 genes and has dedicated videos to its role in aging, cognition, and disease prevention. Her most striking citation is a study of 12,000+ people showing a 40% reduction in dementia risk with vitamin D supplementation over a decade. She links deficiency to accelerated epigenetic aging (equivalent to 5 extra years), increased cancer mortality, and impaired immune function. She notes that 70-80% of the population has suboptimal levels due to indoor lifestyles, sunscreen use, and latitude. She recommends D3 supplementation for most people.

Dr. Rhonda Patrick here. A new study found that vitamin D supplementation was associated with a 40% lower risk of dementia over a decade. After just 5 years, 84% of the vitamin D supplement users were dementi free compared to 68% of the non-users. This was a study of over 12,000 people. And vitamin D reduced dementia risk by around 33% in adults with mild cognitive impairment and also had APOE E4. This is a key genetic risk factor for neurodeenerative diseases. Up to 25% of the population has one of these alals and it can double the risk of Alzheimer's disease if you have one of them.

▶ 00:00 · This Supplement Could Cut Your Dementia Risk By 40%

5 more clips

• 03:09 · This Supplement Could Cut Your Dementia Risk By 40%
• 02:41 · The Vitamin D Sweet Spot and Its Relationship To Aging
• 00:43 · Dr. Rhonda Patrick: Optimizing Longevity with Micronutrients & Vigorous Exercise
• 00:00 · How Vitamin D, Omega-3s, & Exercise May Increase Longevity | Dr. Rhonda Patrick
• 00:00 · How Micronutrients & Exercise Ameliorate Aging | Dr. Rhonda Patrick

Bryan Johnson Includes in Protocol

Johnson includes vitamin D in his broader longevity protocol, though it is not a central focus of his content. His most relevant coverage comes in the context of bone health — his 'How Weak Are Your Bones?' video covers nutrition pillars including vitamin D alongside calcium, protein, and phosphorus. He emphasizes safe sun exposure for vitamin D while warning about UV damage to skin and collagen. His approach is systemic and data-driven: vitamin D is one component in a comprehensive stack rather than a standalone recommendation.

3 more clips

• 01:24 · How Weak Are Your Bones? (Test & Fix)
• 00:36 · How To Not Look Old (Guest: Peter Attia)
• 04:57 · Your House Is Making You Sick (15 Solutions)

Dr. Mark Hyman Strongly Recommends as Essential

Hyman is one of the two strongest advocates for vitamin D supplementation, discussing it across at least 123 videos. He calls it one of the essential supplements 'everybody needs' and has multiple dedicated videos on the topic. He recommends vitamin D3 (not D2) combined with K2 for optimal calcium metabolism, targeting blood levels of 50-80 ng/mL. He links deficiency to cancer, cardiovascular disease, diabetes, depression, autoimmune conditions, and overall mortality. He emphasizes that fortified foods often use the inferior D2 form and that modern indoor lifestyles make supplementation necessary for most people. He also specifically addresses the vitamin D + magnesium synergy in a dedicated video.

…real ideal and they don't even recommend the right vitamin D form it should be vitamin D3 which is the active form not vitamin D2 and there's often poor conversion the optimal reference range is is probably 45 to 75 up to 100 is fine as well in fact levels up to 250 have been shown to be very safe now if you if you look one study they did of Health young adults who took 10,000 units a day for three months there were no adverse effects on these people lifeguards have levels of over 200 nanograms per D ler so I like to get my patients probably around 50 or so 50 to…

▶ 10:07 · The Truth About Vitamin D & Warning Signs Your Body Is Deficient | Dr. Mark Hyman

5 more clips

• 10:45 · Vitamin D Deficiency? Here's What's Really Happening
• 07:03 · The INSANE BENEFITS of Vitamin D & How To Get It SAFELY! | Dr. Mark Hyman
• 02:15 · My Favorite Supplements for Optimal Health & Longevity | Dr. Mark Hyman
• 00:00 · How Vitamin D And Magnesium Work Together
• 19:30 · The 6-Step Protocol To Stop Decline, Stay Young & Reverse Aging After 40+ | Dr. Mark Hyman

How much vitamin D should you take per day?

Most experts suggest 1,000-5,000 IU of vitamin D3 daily, depending on your baseline blood level and body weight. Hyman recommends testing first and targeting 50-80 ng/mL, and notes higher-BMI individuals may need more since body fat sequesters vitamin D. Patrick says most people need supplementation given widespread deficiency.

When should you take vitamin D?

Take vitamin D with a fat-containing meal for better absorption, since it is fat-soluble. Morning or midday is preferred — there is some evidence that evening doses can interfere with melatonin production. It pairs well with omega-3 at a meal, as both are fat-soluble and can be taken together for optimal absorption.

Is vitamin D3 better than D2?

Yes — the experts recommend vitamin D3 (cholecalciferol), not D2. Hyman notes that fortified foods often use the less effective D2 form and recommends D3, ideally with K2. Attia is explicit too: when he lists vitamin D, he means D3, dosed based on blood-level monitoring.

Should you take vitamin D with K2 or magnesium?

Both pairings matter. Hyman recommends combining D3 with K2 so calcium goes to bones and teeth rather than depositing in arteries. He also has a dedicated video on magnesium, which is required for the enzymatic conversion of vitamin D into its active form — without enough magnesium, supplementation may be ineffective.

Is 5000 IU of vitamin D too much?

Not necessarily. The experts' range runs 1,000-5,000 IU daily depending on baseline and body weight, but the upper safe limit is generally considered 4,000 IU/day without medical supervision. Higher-BMI individuals may need more since body fat sequesters vitamin D. Attia warns about hypervitaminosis D, so testing your level first helps you dose appropriately.