5 Needs context
Permanent memory formation occurs during REM sleep.
"Isn't there a body of literature about memory being made permanent during REM? Yes, memory is linked and mood is linked." (said at 0:14:35)
The speaker claims there is a body of literature showing memory is made permanent during REM sleep, and that memory and mood are linked. In sleep neurobiology, long-term memory formation (systems consolidation) is heavily established as occurring during sleep, but the primary transfer of declarative memories to permanent neocortical storage is predominantly driven by slow-wave / non-REM (NREM) sleep via hippocampal-neocortical replay (sharp-wave ripples, slow oscillations, and spindles). REM sleep contributes distinctly to emotional memory processing, mood regulation, schema integration, and procedural memory consolidation rather than being the sole or primary phase where memories are made permanent.
- context: Sleep's contribution to memory formation. (Physiological reviews 2026) · cited 21x in the literature
"In this concept, the repeated neuronal replay of encoded representations, particularly in the hippocampus, in conjunction with brain oscillations hallmarking non-rapid eye movement (non-REM) sleep, provide mechanisms for regulating information flow across brain networks. This interplay drives the consolidation of newly encoded memory into neocortical long-term stores" (abstract, results, passage verified)
pubmedfull study (doi) - context: Systems memory consolidation during sleep: oscillations, neuromodulators, and synaptic rem… (BMB reports 2025) · cited 7x in the literature
"during NREM sleep, the coupling of slow-oscillations, spindles, and sharp-wave ripples facilitates hippocampal-cortical transfer of memory representations, while REM sleep theta oscillations contribute to memory integration, abstraction, and emotional tagging." (abstract, results, passage verified)
pubmedfull study (doi) - context: Sleep and memory consolidation: Neural and cognitive perspectives. (Progress in brain research 2026)
"Distinct contributions of sleep stages are highlighted, with slow-wave sleep (SWS) supporting declarative memory consolidation through hippocampal-neocortical replay mechanisms, and Rapid eye movement (REM) sleep enhancing procedural and emotional memory processing." (abstract, results, passage verified)
pubmedfull study (doi)
Sunscreen use blocks the skin's ability to synthesize vitamin D.
"If you tell them that they can use sunscreen wisely, and it blocks the ability to make vitamin D" (said at 0:43:31)
Sunscreen filters UVB radiation, which is required for cutaneous vitamin D3 synthesis. In controlled experimental and in vitro conditions, proper sunscreen application substantially abrogates vitamin D3 production. However, in real-world practice and field trials, regular sunscreen use has a modest or negligible impact on circulating 25(OH)D levels (or causes only small reductions, around 2 ng/mL), largely because people typically apply less than the recommended thickness, do not reapply frequently, or experience incidental sun exposure.
Coenzyme A is required for the biosynthesis of cortisol in the human body.
"Coenzyme A is responsible for making cortisol." (said at 0:46:19)
Coenzyme A (CoA, derived from pantothenic acid/vitamin B5) is fundamentally required for cellular metabolism and de novo cholesterol synthesis via acetyl-CoA and 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA), as well as fatty acyl-CoA utilization and cholesterol ester storage in adrenal tissue. Because cholesterol is the obligatory precursor for steroidogenesis, CoA is necessary upstream for substrate provision. However, the enzymatic cascade directly converting cholesterol into cortisol within the adrenal cortex is mediated by steroidogenic cytochrome P450 enzymes (e.g., CYP11A1, CYP17A1, CYP21A2, CYP11B1) and hydroxysteroid dehydrogenases using NADPH and oxygen, rather than CoA acting as the primary steroid-synthesizing agent.
When UVB light strikes cholesterol in the skin, 15 to 20 other photoproduct chemicals are synthesized alongside vitamin D3.
"Number two, it turns out there's a lot of literature that shows that vitamin D is not the only thing made by UVB hitting your skin. And what it's hitting is cholesterol. And that cholesterol is changed as a chemical called D3. But there are probably 15, 20 other chemicals that are being made at the same time." (said at 1:32:26)
The speaker's statement is broadly accurate regarding photochemistry, but simplifies key biochemical details. UVB radiation in the skin primarily strikes 7-dehydrocholesterol (7-DHC, an immediate precursor in cholesterol biosynthesis located in epidermal cell membranes), rather than mature cholesterol itself. Upon UVB exposure, 7-DHC photolyzes into previtamin D3, which thermally isomerizes into vitamin D3. Previtamin D3 and vitamin D3 undergo further photochemical and enzymatic reactions forming numerous photoisomers and metabolites (such as lumisterol, tachysterol, suprasterols, toxisterols, and CYP11A1-derived hydroxyderivatives), amounting to over a dozen distinct photoproducts.
- supports: An evaluation of the biologic activity and vitamin D receptor binding affinity of the phot… (The Journal of nutritional biochemistry 2000) · cited 36x in the literature
"In conclusion, vitamin D3, its photoisomers and the photoisomers of previtamin D3 have antiproliferative activity in cultured human keratinocytes." (abstract, conclusions, passage verified)
pubmedfull study (doi) - supports: Novel vitamin D photoproducts and their precursors in the skin. (Dermato-endocrinology 2013) · cited 75x in the literature
"Novel metabolic pathways initiated by the enzymatic action of CYP11A1 on 7DHC (7-dehydrocholesterol), ergosterol, vitamins D3 and D2 were characterized with help of chemical synthesis, UV and mass spectrometry and NMR analyses... The resulting 5,7-dienes can be transformed by UVB to corresponding, biologically active, secosteroids." (abstract, passage verified)
pubmedfull study (doi) - context: Sunlight and Vitamin D: A global perspective for health. (Dermato-endocrinology 2013) · cited 1149x in the literature
"During exposure to sunlight 7-dehydrocholesterol in the skin absorbs UV B radiation and is converted to previtamin D3 which in turn isomerizes into vitamin D3. Previtamin D3 and vitamin D3 also absorb UV B radiation and are converted into a variety of photoproducts some of which have unique biologic properties." (abstract, passage verified)
pubmedfull study (doi)
Pellagra is a niacin deficiency caused by pure corn gruel diets in institutionalized populations in the southern United States in the 1930s and 1940s.
"The same thing about pellagra, which is actually a niacin deficiency in adults and children that were institutionalized in the South of the United States in the '30s and '40s and fed corn gruel as their only food." (said at 1:47:04)
Pellagra is established to be caused by a dietary deficiency of niacin (vitamin B3, or its precursor tryptophan), famously linked to maize/corn-dominated diets lacking bioavailable niacin. In the American South, major epidemiological investigations in institutionalized populations (such as orphanages, mental hospitals, and prison farms) were conducted primarily by Joseph Goldberger between 1914 and the late 1920s, demonstrating that the corn-heavy, monotonous diets caused the disease and dietary diversification cured it. Niacin was identified as the curative factor in 1937, leading to mandatory flour and cornmeal enrichment programs in the 1940s. The claim correctly identifies the biochemical cause (niacin deficiency), dietary cause (corn-based diet), and setting (institutionalized and impoverished populations in the Southern United States), though the primary epidemic and institutional experiments peaked in the 1910s–1920s rather than originating solely in the 1930s–1940s.
- supports: Environment, population, and biology: a short history of modern epidemiology. (Perspectives in biology and medicine 2006) · cited 7x in the literature
"In the United States, Joseph Goldberger found no evidence for the hypothesis of contaminated maize or for a microbiological agent, but recognized the central role of nutrition. The "cure" Goldberger proposed was land reform, but he continued studying the disease from a mechanistic point of view; shortly after his death, niacin deficiency was identified as the cause of pellagra." (abstract, passage verified)
pubmedfull study (doi) - supports: Chapter 30: historical aspects of the major neurological vitamin deficiency disorders: the… (Handbook of clinical neurology 2010) · cited 104x in the literature
"In the United States, pellagra became epidemic among poor Southerners in the early 20th century, in part because of economically-driven reliance on monotonous, nutritionally inadequate diets, combined with new manufacturing methods that removed vitamins from processed grain. From 1914-1929, Goldberger completed well-designed epidemiologic investigations, tested theories with human experiments, and utilized an animal model ("black tongue" in dogs) - all strongly supporting a dietary deficiency explanation for pellagra over prevailing toxic and infectious theories." (abstract, results, passage verified)
pubmedfull study (doi)
Unverified means no publication matching the claim was located; it does not prove the claim false. Spotted an error? See the corrections policy - disputes from the people quoted are prioritized.