The Diary of a CEOWhy sunlight beats vitamin D pills for your mitochondria
How brief daily sun, sauna sessions, and outdoor time fuel mitochondria; he argues vitamin D pills miss the infrared signal sunlight delivers.
CHAPTERS
- 0:00 – 12:00
Opening Story: A 15-Year-Old Saved by Sunlight
Seheult opens with a dramatic case: a 15-year-old leukemia patient develops a lethal fungal lung infection, loses one lung, and is given two days to live. Granted his dying wish to go outside, he spends days in sunlight plus short red‑light "firefly" sessions, and his infection rapidly regresses without any other treatment changes.
- •Boy with lymphoblastic leukemia and a severe fungal lung infection is deemed terminal after losing his left lung.
- •Doctors refuse further invasive interventions and estimate two days to live; his only request is to go outside.
- •Staff move his hospital bed outdoors with non‑invasive ventilation and a red‑light device ("firefly").
- •Over 5 days, his white count and oxygen needs fall; CT scan shows ~60–70% of lung infection resolved.
- •He survives, returns home, and continues cancer care—prompting Seheult to question why sunlight isn’t routinely used therapeutically and to advocate for getting hospital patients outside.
- 12:00 – 31:00
Eight Pillars of Health: The NEWSTART Framework
Seheult frames health as a chain of organ "links" that erode over time, often treated with drugs that help one link at the expense of others. He introduces eight lifestyle pillars—Nutrition, Exercise, Water, Sunlight, Temperance, Air, Rest, and Trust—that can strengthen all links simultaneously, emphasizing their side‑benefits versus the side‑effects of medications.
- •Modern medicine often rescues the weakest organ "link" (e.g., stroke, heart disease) by stressing other links via drugs.
- •He argues physicians must also address lifestyle factors preventing recurrence, not just acute rescue.
- •Introduces NEWSTART: Nutrition, Exercise, Water, Sunlight, Temperance, Air, Rest, Trust.
- •Exercise is described as having "side benefits"—reducing stroke and depression while improving multiple organs.
- •Water includes both hydration and external use (heat/cold therapy), which he later ties to immune function.
- •Temperance = avoiding toxins like smoking, alcohol abuse, amphetamines.
- •Rest includes both nightly sleep and a weekly rest from digital and work demands.
- •Trust (faith/spirituality) is highlighted as a scientifically measurable buffer against stress and depression.
- 31:00 – 45:00
Sunlight Misconceptions, Vitamin D, and Mitochondrial Dysfunction
The conversation pivots to sunlight as Seheult’s current focus, shaped by his ICU experience in COVID. He explains how many severe COVID patients had chronic diseases linked to mitochondrial dysfunction and why high vitamin D levels predicted better outcomes, yet supplementation alone often failed—leading him to suspect sunlight itself was the causal factor.
- •Early COVID projections focused on respiratory disease, but ICU deaths were mostly obese, diabetic, cardiac, renal, and dementia patients.
- •These chronic conditions share mitochondrial dysfunction: aging reduces mitochondrial energy output by ~70%.
- •Mitochondrial "engines" overheat via oxidative stress; they need an internal "cooling system."
- •Vitamin D status strongly predicted COVID mortality risk, but hospital supplementation didn’t rescue outcomes.
- •Seheult proposes vitamin D was a *marker* of sun exposure: people with higher vitamin D spent more time outdoors.
- •He notes COVID’s use of the ACE2 receptor, which normally helps mitigate oxidative stress—its inactivation makes mitochondrial "engines" run hot, explaining worse outcomes in already metabolically compromised patients.
- 45:00 – 1:04:00
How Infrared and Red Light Support Mitochondria and Melatonin
Drawing on a 2019 paper by Reiter and Zimmerman, Seheult explains how different sunlight wavelengths interact with the body. Infrared (and some visible red) penetrate deeply, upregulating mitochondrial melatonin production and improving energy output, while shortwave UVB is mostly limited to skin and vitamin D production.
- •Physics analogy: low-frequency (long‑wavelength) sounds and light travel further and penetrate deeper (e.g., thunder rumble).
- •Infrared light from the sun can penetrate up to ~8 cm, interacting directly with mitochondria.
- •Mitochondria generate oxidative stress like heat in an engine; they need a "cooling" system.
- •Mitochondrial melatonin (distinct from pineal melatonin for sleep) acts as an internal antioxidant/coolant.
- •Infrared radiation stimulates mitochondrial melatonin and other protective pathways, improving efficiency.
- •This mechanism could unify sunlight’s benefits across tissues: better liver function (less fatty liver), heart performance, and brain health (less dementia).
- •Red/infrared light therapy devices mimic a slice of the solar spectrum; research by Glen Jeffery shows 670 nm light improves retinal mitochondrial function, vision, and systemic glucose handling in small human trials.
- •Short exposures (~15–20 minutes) appear sufficient to trigger mitochondrial changes; longer sessions don’t add much in that time window.
- 1:04:00 – 1:18:00
Clinical Evidence: Infrared Jackets, COVID, and Hospital Sun Therapy
Seheult highlights early interventional data: a small Brazilian trial of infrared jackets in hospitalized COVID-19 patients and his own experience wheeling a severely hypoxic COVID patient outside daily. These examples illustrate how low‑risk light exposure could shorten hospital stays and possibly reduce the need for invasive ventilation.
- •Brazilian RCT: 30 hospitalized COVID patients wore jackets embedded with 940 nm LEDs for 15 minutes/day over 7 days; half had lights turned on, half off (blinded).
- •Those receiving infrared had statistically significant improvements in oxygenation, breath strength, white blood cell patterns, heart and respiratory rates, and a shorter average hospital stay (8 vs. 12 days).
- •This magnitude of benefit rivals or exceeds many drug approvals, yet came from a non‑pharmaceutical intervention.
- •Post‑study, Seheult adopted a practice of getting hospitalized COVID patients outside for sunlight when possible.
- •He describes a man on high‑flow oxygen (35 L/min at 100% O2) in a dark room whose first words were "How much time have I got?"; after daily sun exposure, his oxygen requirement fell rapidly and he went home on day five without supplemental oxygen.
- •He stresses these are anecdotes and small studies, but given the low risk and plausible mechanism, they merit larger trials and immediate pragmatic use.
- 1:18:00 – 1:30:00
Epidemiology: Latitude, Seasons, and Sunlight’s Role in Mortality
The discussion zooms out to population-level patterns connecting sunlight, latitude, and death rates. Seheult reviews data showing COVID surges tracking seasonal sunlight decline across Europe and studies in the US, UK, and Italy linking higher ambient sunlight to lower COVID mortality—independent of vitamin D.
- •Autumn 2020 COVID waves in Europe progressed from north to south in step with declining sunlight, not temperature or humidity; Greece, with more sunlight, surged last.
- •University of Edinburgh analyses in the US, UK, and Italy found that regions with more sunlight had lower COVID-19 mortality, despite minimal winter vitamin D production at those latitudes.
- •This suggests sunlight’s protective effects go beyond vitamin D—again pointing to infrared/mitochondrial mechanisms.
- •Mortality from many causes (influenza, cardiac, kidney, infections) peaks shortly after the shortest day of the year and is lowest after the longest day, even when holiday gatherings (e.g., Christmas) are constant, as demonstrated by opposite seasonal mortality patterns in Australia.
- •Day length acts as a proxy for cumulative sun exposure; "seasonal adjustments" in mortality stats are essentially correcting for light exposure differences.
- 1:30:00 – 1:43:00
Sunlight, Cancer, and Melanoma: Rethinking Risk–Benefit
Seheult cites large Swedish and UK studies showing that regular sun exposure correlates with lower mortality from cardiovascular and non‑skin cancers, without clear increases in melanoma incidence. He contrasts this with decades of public health messaging framing the sun as an almost purely carcinogenic risk.
- •Swedish cohort (20,000–30,000 women, ~20 years): women with the highest sun exposure had the lowest mortality from cancer, CVD, and non‑CVD causes.
- •Women with minimal sun exposure had mortality risks comparable to smokers, suggesting sun avoidance is as dangerous as smoking in that dataset.
- •Dose–response trends (low vs. moderate vs. high sun) satisfy Bradford Hill criteria suggesting possible causation, analogous to smoking–lung cancer evidence.
- •UK Biobank study (300k+ people, both sexes) by dermatologist Richard Weller found more sunlight correlated with reduced non‑skin cancer mortality, with no significant increase in melanoma incidence.
- •Weller’s op‑ed "Sunlight: Time for a Rethink" argues that current sun‑avoidance messaging neglects these systemic benefits and that moderate sun exposure should be recommended.
- 1:43:00 – 2:05:00
Practical Sunlight Guidance, Devices, and Cloudy Climates
The host and Seheult move into practical questions: how to safely get sun, the role of red‑light devices like Bon Charge masks, and what to do in cloudy countries. They differentiate between natural light’s broad-spectrum benefits and targeted device use.
- •Optimal times for sun: mornings and late afternoons when UV is lower but infrared still abundant, reducing burn risk while supporting mitochondria and circadian rhythm.
- •Midday sun offers maximum infrared but also intense UV; newcomers or fair-skinned individuals may need to limit exposure or use clothing and hats.
- •For mitochondrial/metabolic effects, any body area can receive light; for circadian entrainment, the eyes matter most.
- •Red‑light devices (masks, panels, saunas) emit visible red plus some infrared; evidence supports localized skin benefits via collagen production and broader systemic mitochondrial effects when applied on larger body areas.
- •Jeffery’s work suggests systemic metabolic improvements from back exposure alone, hinting that mitochondria communicate systemically.
- •Devices are most useful for people with low natural sun exposure (e.g., shift workers or during dark winters); if you already get ample sun, added device benefits may be marginal—like an extra lemon for someone already eating a vitamin‑C‑rich diet.
- •In cloudy countries, outdoor light still provides more infrared than indoor environments; clouds absorb some infrared but don’t eliminate it.
- 2:05:00 – 2:30:00
Artificial Light, Circadian Rhythm, SAD Lamps, and Nighttime Darkness
Attention shifts to how artificial lighting affects mood and circadian rhythms. Seheult explains the biological impact of LED/fluorescent lighting, the role of bright morning light (including SAD lamps), and why dark nights are crucial for melatonin and sleep quality.
- •Modern LEDs are engineered to emit narrow, visible spectra (often blue-heavy) and little to no infrared, unlike incandescent, candle, or sunlight, which are full-spectrum.
- •For the first time in human history we regularly receive blue light without corresponding red/infrared, with unknown long‑term consequences.
- •Glen Jeffery’s preprint swapping LED for incandescent lighting improved color differentiation by ~25% in older subjects, likely by boosting retinal mitochondrial function.
- •SAD lamps (10,000 lux) used for 20 minutes in the morning can reset circadian rhythms and reduce seasonal depression by mimicking bright morning sky light through the eyes.
- •They are a partial replacement when direct sun isn’t available, but they don’t provide infrared/mitochondrial benefits.
- •At night, any light—especially blue but not limited to blue—suppresses pineal melatonin and shifts circadian timing later, making it harder to fall asleep.
- •Blue-blocking glasses and "night mode" screens help but don’t solve the problem; complete darkness is ideal for sleep.
- •Night lights, LED displays in bedrooms, and bright device use near bedtime are discouraged; sleep masks can help when room darkness is impossible.
- •Reading a physical book under a dim lamp disrupts melatonin less than backlit screens like Kindles; candlelight is physiologically better but poses fire risk.
- 2:30:00 – 2:46:00
Vitamin D: Benefits, Limits, and Safe Supplementation
They clarify vitamin D’s legitimate benefits and limitations. While Seheult criticizes the belief that supplements can fully replace sunlight, he supports supplementation when sunlight is inadequate, with monitoring to avoid excess.
- •Randomized trials show daily vitamin D (~2,000 IU) reduces acute respiratory infections and lowers risk of all‑cause autoimmune diseases (e.g., rheumatoid arthritis, Crohn’s).
- •Vitamin D acts both as a vitamin and hormone, influencing gene transcription in many tissues, including immune cells and calcium metabolism.
- •Roughly 1 billion people are deficient, and about half the global population has insufficient vitamin D, driven by indoor lifestyles and sun avoidance.
- •Dark-skinned individuals at high latitudes (like the UK) are at particular risk and often need more outdoor time or supplementation.
- •Vitamin D is fat‑soluble; overdosing can cause hypercalcemia, though this is rare at typical doses. Periodic blood testing is recommended for regular supplement users.
- •Food sources include fatty fish and mushrooms, but sunlight remains the most efficient natural source when available.
- 2:46:00 – 3:08:00
Water, Heat–Cold Therapy, Fever, and the Innate Immune System
The "Water" pillar shifts from hydration to external water use. Seheult explains how heat (saunas, hot baths) and brief cold exposure can augment the innate immune response via fever-like effects and white blood cell mobilization, highlighting interferon’s central role in antiviral defense.
- •The immune system has two arms: innate (rapid, non‑specific) and adaptive (antibodies, slower and mutation‑sensitive).
- •Interferon is the innate system’s key antiviral signal; every successful virus evolves mechanisms to evade it.
- •Mild elevation of core temperature (37→38°C) dramatically increases regulatory proteins that boost interferon production.
- •Fever is a built-in defense that inhibits viral replication and signals immune activation; routinely suppressing it with antipyretics may blunt this response (unless fever is dangerously high).
- •Because water has high specific heat, hot baths, saunas, or hot compresses can raise core body temperature safely to trigger interferon increases—"artificial fever."
- •Cold water at the end causes vasoconstriction, helping maintain internal heat longer and demarginate white blood cells from vessel walls into circulation.
- •Finnish sauna data show dose‑response reductions in cardiovascular mortality with frequent sauna use (4–7 days/week vs. once/week).
- 3:08:00 – 3:30:00
Air, Nature, Plants, and CO₂: Why the Outdoors Matters
Seheult broadens the "Air" pillar to include not just oxygen and low pollution, but also beneficial airborne compounds from plants and trees. He connects forest bathing research, urban greening interventions, and CO₂ management in indoor spaces to cognitive and immune performance.
- •Air quality is more than just fewer pollutants; outdoor air often contains a beneficial microbiome and plant-derived compounds.
- •Japanese studies in Hinoki cypress forests show that exposure to tree phytoncides increases NK cell number and activity and enzymes that break down pathogens, with effects lasting about seven days.
- •The Green Heart Study: planting 8,000 trees in a 4‑square‑mile urban area in Louisville lowered residents’ hs‑CRP by 13–20% and is estimated to cut stroke risk by 10–15%, without socioeconomic or behavioral interventions.
- •Trees and vegetation also reflect infrared light, amplifying beneficial light exposure in green spaces compared to concrete environments.
- •Green environments correlate with lower diabetes, hypertension, mortality, and depression.
- •Indoors, CO₂ can accumulate and impair cognition; cracking windows, avoiding recirculation-only car settings, and using CO₂ monitors can help maintain better air quality.
- 3:30:00 – 4:10:00
Trust, Faith, Forgiveness, and Mental Health
The final NEWSTART pillar—Trust—focuses on faith, spirituality, and their measurable associations with mental and physical health. Seheult reviews studies on divine forgiveness, conditional vs. unconditional forgiveness, and their downstream impact on depression, anxiety, and somatic symptoms.
- •Research suggests individuals with a supportive faith in God or a higher power tend to have lower depression and anxiety and better stress coping.
- •A central study divided people by conditional vs. unconditional forgiveness; unconditional forgivers had less depression, less somatization, and less end‑of‑life anxiety.
- •Belief that "God has forgiven me" was ~2.5 times more likely to produce unconditional forgiveness, which was then associated with those positive mental health outcomes.
- •Randomized trials show cognitive behavioral therapy is more effective when integrated with a patient’s existing faith framework (when present).
- •Conversely, a view of God as punitive or vindictive is associated with worse mental health, highlighting that *the quality* of belief matters.
- •Seheult stresses that spiritual interventions should never be imposed without consent, especially in clinical settings.
- 4:10:00 – 4:40:00
End-of-Life Perspectives, Miracles, and Humility in Prognosis
Drawing on his ICU experience, Seheult reflects on death, prognostication, and a case he considers miraculous: a young man with severe anoxic brain injury awakening and recovering months after doctors had given up hope. This experience reshaped his humility about predicting outcomes.
- •Many patients at the end of life feel ready to go and decline aggressive life-sustaining interventions even when survival is technically possible.
- •Seheult recounts a 20‑something man with testicular cancer who suffered profound brain damage from lack of oxygen during surgery and was deemed permanently vegetative.
- •His wife remained convinced he would recover, cared for him daily, and reported a dream that he would come home.
- •Weeks later, Seheult noticed purposeful eye focus and a weak wave; over months, the patient slowly recovered and eventually walked back onto the unit with his wife to thank the staff.
- •The case made Seheult deeply skeptical of overly confident prognoses like "you’ll never walk again" or "you have two years to live," because much of biology remains unknown.
- 4:40:00 – 4:51:00
Melatonin Supplements: When and How to Use Them Safely
They briefly address melatonin supplements, distinguishing between the mitochondrial melatonin discussed earlier and the pineal melatonin used as an over-the-counter sleep aid. Seheult advises cautious, targeted use rather than chronic high-dose consumption.
- •Low-dose melatonin (up to ~5 mg) can help with sleep onset difficulties, shifting circadian rhythm earlier, and jet lag.
- •High doses may cause irritability and mood changes, and there are theoretical concerns about suppressing endogenous production, though data are limited.
- •He doesn’t recommend high-dose, long-term melatonin without a specific indication; it’s better used as a targeted tool, alongside proper light/dark hygiene.
- 4:51:00
Science and Scripture: The Body as a Temple
In response to a closing question about rarely discussed interests, Seheult describes his fascination with scientific patterns he sees in biblical descriptions, particularly the temple structure and the body-as-temple metaphor. He draws parallels between ancient sanctuary design and modern cellular biology.
- •Paul’s statement "your body is the temple of the Holy Spirit" inspired Seheult to compare biblical temple design with the structure of the body.
- •He notes that Moses’ sanctuary (and some Hindu temples) is described as a three-part structure: outer court, holy place, and most holy place, paralleling blood–interstitial space–cell/nucleus compartments.
- •He likens the altar of sacrifice to the blood system, the laver (water basin) to interstitial fluid, and the inner rooms to the cell and nucleus.
- •The Ark of the Covenant holding two stone tablets (moral "code" of life) is compared to the nucleus with two DNA strands encoding biological life; damage leads to disease and death.
- •He emphasizes that these correspondences predate modern understanding of cells, circulation, and DNA by millennia, which he finds intellectually intriguing, regardless of one’s belief stance.
