Snapshot · The Diary Of A CEO with Steven Bartlett
Vitamin D is synthesized on the skin like a hormone and acts on DNA receptors — calling it a vitamin was a historical mistake that shaped decades of bad medical guidance.
Where this was said
At 40:40 · chapter starts 40:36
This chapter delivers the episode's sharpest reframe. Dr. Gominak explains that vitamin D is not a dietary nutrient for humans in any meaningful biological sense — it is made on bald human skin exactly as it is on animal fur, where animals lick it off and absorb it orally. Humans can't lick their skin, so we absorb it directly through the skin. Eating salmon for vitamin D, she says, is like eating salmon to get a normal menstrual cycle from salmon oestrogen: it is that foreign. The classification error happened in the early twentieth century before the distinction between vitamins and hormones was well understood, and medicine doubled down on it in the 1980s when it decided vitamins were for 'lesser humans' and pushed vitamin D onto pharmacy shelves over the counter. She explains how this compares to oestrogen, testosterone, and thyroid — all managed via blood-level monitoring in tight bands because too much and too little are both harmful. She rejects the flat-dose approach used in virtually all vitamin D research (e.g. 4,000 IUs regardless of blood level) as fundamentally wrong for a hormone, which is exactly why that research keeps producing null or contradictory results. The Endocrine Society, she notes, acknowledged this flaw in 2004 but still chose to walk away from the question rather than fund better studies.
Vitamin D is synthesized on the skin exactly like a hormone, acts on DNA receptors inside cells, and should be managed like estrogen or testosterone with blood-level monitoring. Calling it a vitamin was a historical error that sent it to the over-the-counter shelf.
Making the first hour of your day high-cortisol and the last hour low-cortisol is described as the single most impactful daily habit for mood, focus, alertness, stress resilience, and sleep quality.
A Washington University in St. Louis study found that a great night's sleep produces attention-improvement effects effectively equal to Ritalin.
In the 4 to 6 hours after exercise, dopamine and norepinephrine are elevated, making you more alert and better able to focus — unless you've exercised to exhaustion.
The physiological sigh — two big inhales followed by a full exhale — was discovered by physiologists in the 1930s and is the fastest way to reduce autonomic arousal.
Doing just 10 deliberate exhales throughout the day can significantly elevate heart rate variability by the evening, by repeatedly activating the vagal sinoatrial node pathway.
For nicotine to have a genuine cognitive-enhancing effect rather than merely rescuing withdrawal deficit, Huberman recommends using it only once or twice per week at 3–6 mg.
Because vaping can be done anywhere and is more palatable, people consume far more nicotine via vaping than they ever did smoking, potentially making vaping more dangerous in aggregate despite being safer per puff.
Huberman reported that two injections of approximately 100–200 micrograms of BPC-157 eliminated persistent shoulder pain that had resisted months of other interventions.
Huberman reported that on nights he used the peptide pinealon, he achieved 2.5 to 3 hours of REM sleep inside 6 hours — an unusually high proportion normally only found in the final hours of longer sleep.
We use essential and analytics cookies to run Vuci. To understand how the site is used: Privacy Policy.
Install Vuci on your phone
Add it to your home screen for a faster, app-like experience.
Install Vuci on your phone
Tap the Share button, then “Add to Home Screen”.
A new version is available
Reload to get the latest Vuci.