Sunlight: Optimize Health and Immunity (Light Therapy and Melatonin)

Sunlight provides so much more than just Vitamin D: learn from Dr. Seheult of about the myriad of benefits from optimizing our exposure to light.

Roger Seheult, MD is the co-founder and lead professor at

He is Board Certified in Internal Medicine, Pulmonary Disease, Critical Care, and Sleep Medicine and an Associate Professor at the University of California, Riverside School of Medicine.

This video was recorded on January 21, 2022

0:00 Intro
6:50 The solar spectrum
13:00 Circadian rhythm highlights and chart
15:15 What is regulated by circadian rhythm
16:30 Circadian dysregulation
22:30 Circadian master clock
26:41 Blue blockers
29:15 Light & mood regulation & seasonal affective disorder
31:14 Dawn simulation light and light therapy box demo
35:45 Light & cortisol
38:15 Melatonin from the pineal gland
42:00 Morning dos and don’ts
44:00 Evening dos and don’ts
48:30 Mitochondria & melatonin
49:45 Melatonin night AND day
51:00 Details of melatonin production
59:00 Melatonin summary
1:02:30 Infrared radiation
1:20:45 Sun exposure & melanoma risk
1:26:00 Sunlight penetrates bone & brain
1:29:00 Sun exposure and Covid-19
1:40:00 Infrared inhibited by glass
1:43:00 Infrared summary
1:53:00 Summary & tips


The Relationship Between Lux, Lumen and Watt (Tachyon) |

Infrared and skin: Friend or foe (J of Photochemistry…) |

Melatonin as a potential anticarcinogen for non-small-cell lung cancer (Oncotarget) |

The efficacy of light therapy in the treatment of mood disorders (AJP) |

Adj. Bright Light Therapy for Bipolar Depression (AJP) |

Effects of artificial dawn on subjective ratings of sleep inertia and dim light melatonin onset (Chronobiology Int) |

Effects of Artificial Dawn and Morning Blue Light… (Chronobiology Int) |

Circadian rhythms in the hypothalamo-pituitary-adrenal (HPA) axis (MCE) |

Reduced cancer incidence among the blind (Epidem) |

Evening use of light-emitting eReaders negatively affects sleep (PNAS) |

Ocular input for human melatonin regulation (NEL) |

Melatonin and the Optics of the Human Body (Melatonin) |

Melatonin in Mitochondria (APS) |

Opportunities.. of Fluorescent Carbon Dots (CPD) |

The health benefits of the great outdoors (Environ) |

Interplay between up-regulation of cytochrome-c-oxidase (Nature) |

Red/Near Infrared Light Stimulates Release of an Endothelium Dependent Vasodilator (FRBM) |

Effect of daylighting on student health (CMSE) |

Shining the Light on Sunshine (Clinical Endo) |

Associations of Outdoor Temperature (JCEM) | />
Relationship between sun exposure and melanoma risk (EJC) |

We cannot post all links and references here (due to video description length limitations) but will post them at the MedCram Blog:

All Dr. Seheult’s videos are at (including more discussion on red light therapy, infrared light benefits, what is melatonin, etc.)

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Video Produced by Kyle Allred
Thanks to Amanda Taylor, PA-C



MedCram medical videos are for medical education and exam preparation, and NOT intended to replace recommendations from your doctor.

#sunlight #covid19 #melatonin

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