Podbit · The Diary Of A CEO with Steven Bartlett
When UVB hits cholesterol in your skin, it makes vitamin D3 and roughly 15 to 20 other anti-inflammatory compounds simultaneously. A supplement only delivers the D3. The rest — the compounds that protect your skin and reduce inflammation — never arrive.
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At 1:23:10 · chapter starts 1:19:43
Bartlett confesses he was recently diagnosed with vitamin D deficiency via a blood test — unsurprisingly, given he jokes he 'lives in a dark bunker.' He bought supplements and assumed the problem was fixed. Dr. Gominak corrects this assumption on two grounds. First, citing researcher Stephanie Seneff, she explains that vitamin D made on skin is sulfated — chemically distinct from supplemental D3 — and may behave differently in the body. Second, when UVB strikes cholesterol in skin it generates not just D3 but approximately 15 to 20 other compounds simultaneously, including anti-inflammatory molecules that protect the skin from the damaging effects of sunlight. None of these accompany the supplement pill. Bartlett produces a selection of fermented foods — kimchi, sauerkraut, kefir, kombucha, yoghurt — and asks whether diet plus sunlight is sufficient for people without serious sleep disorders. Dr. Gominak says yes: for people without significant sleep problems, the healthier path is to be outside more and include fermented foods, which deliver the equivalent of B50 through their bacterial content. Supplements are the fast, clinical-certainty path for those who are already significantly disordered.
Spike your cortisol in the first 1–3 hours of your day — with sunlight, hydration, exercise, or caffeine — and you set up elevated mood, focus, and stress resilience for the rest of the day. Miss that spike and you get a flat cortisol curve: brain fog, poor learning, and bad sleep. The bookend is equally important: dim lights, no caffeine, and wind down the final hour.
Bottom-up impulses — just eat the cookie, keep scrolling — are driven by deep brain structures. Top-down prefrontal control is the thing that lets you wait, learn, and grow. Every small act of choosing the harder thing, from picking up trash to doing the workout you dread, greases that top-down circuit — and it transfers to everything else.
A Washington University in St. Louis study found that the attention-improvement effects of Ritalin are effectively equal to a great night's sleep. Stimulants also stunt growth and reduce sleep quality. The new direction is combining lower medication doses with genuinely better sleep — not replacing sleep with pharmacology.
Two big inhales through the nose, then a full exhale to empty — that's the physiological sigh. It fires a specific vagal pathway to slow your heart rate, offload CO2, and tip the autonomic nervous system toward calm instantly. Doing just 10 deliberate exhales throughout the day measurably elevates HRV by nighttime.
Presence isn't a state you fall into — it's something you actively produce by anchoring perception to the immediate environment. Ask 2–3 trivially specific questions about your surroundings (how many cans, what does it smell like) to pull your brain out of past/future mode. Then deliberately choose what to think or say next. That's it.
Acknowledge the thing, feel all of it, uncouple the emotion from the memory, then transmute the experience into something meaningful. Most people stall at step 2 — feeling the feelings — and never reach uncoupling. An entire generation is stuck there, confusing emotional processing for healing. Moving through all four is the actual path out.
Nicotine creates a uniquely alert-and-calm state ideal for learning — but only at low doses used occasionally. If you're using 3–6 mg pouches multiple times a day, you're not getting a cognitive enhancement, you're just rescuing yourself from withdrawal. For a genuine performance effect, use it once or twice per week at most.
Two injections of BPC-157 (100–200 mcg) eliminated shoulder pain Huberman couldn't shift for months. The peptide pinealon gave him 2.5–3 hours of REM sleep inside 6 hours — an effect that persisted into subsequent nights and scaled down to just once per week. Neither is in the book because the human data aren't there yet, but the animal evidence is strong.
Long, slow cardio builds capillary networks and mitochondrial richness; high-intensity intervals push VO2 max. You don't need huge volumes of either. Huberman's protocol: one 45–60 minute long slow session, one near-maximal effort HIIT session (Airdyne 20-on/10-off for 6–8 rounds), and one medium 30-minute effort per week. That's the complete cardio picture.
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