Did you know…

A running collection of compact physiological facts. Each one is short enough to stand alone and specific enough to be verified. Together they form the substrate from which the longer arguments on this resource are built.

The list grows as new pieces are written. Every article on this resource contributes at least one entry.

• Vitamin K2 intake predicts arterial calcification and cardiac mortality. K1 does not.

  The Rotterdam Study of 4,807 subjects free of cardiovascular disease at baseline showed that dietary vitamin K2 intake was inversely associated with aortic calcification and with cardiovascular mortality. Vitamin K1 was not linked with any of these outcomes. Yet the K1 form is what fortification programs and standard supplementation address.

• Humans, primates, guinea pigs, and one fruit bat are the only mammals that do not make their own vitamin C

  The vast majority of mammals synthesize their own vitamin C. A 155-pound goat produces roughly 13 grams per day. Extrapolated from the synthesis rate in rats, the equivalent human production would be about 2 to 3 grams per day, if the enzyme were not broken. The 90 mg RDA is calibrated to prevent scurvy, not to match what the body would make on its own.

• Testosterone given to zinc-deficient animals fails to restore muscle

  In zinc-depleted rats, replacing the testosterone that fell with zinc depletion does not restore muscle mass, muscle RNA content, or muscle strength. The transcriptional machinery that testosterone signals to requires zinc to function. This is a peer-reviewed finding from 1997 that the anabolic-testosterone marketing register has never absorbed.

• Taurine supplementation extends lifespan in mice and improves healthspan in monkeys

  In 2023, an international team led by Vijay Yadav at Columbia showed in Science that taurine supplementation extended average lifespan by 10 to 12% in mice and improved multiple healthspan markers in monkeys. A 2025 NIA re-analysis has since questioned taurine's status as a human aging biomarker, but the animal intervention data stand.

• Statins deplete coenzyme Q10 by the same mechanism that lowers cholesterol

  The mevalonate pathway that statins block to lower cholesterol also produces coenzyme Q10, the electron carrier at the heart of mitochondrial energy production. Statin-induced CoQ10 depletion in blood and tissue is documented in animal and human trials. Whether routine co-supplementation prevents muscle symptoms remains debated, but the mechanism itself is not.

• Without selenium, your body cannot convert T4 into active thyroid hormone

  The enzymes that convert the prohormone T4 into active T3 (the iodothyronine deiodinases) are selenoproteins. Each one contains selenium in the form of selenocysteine, the so-called 21st amino acid. Without adequate selenium, T4 accumulates while T3 stays low, and the patient can have a normal TSH and still be functionally hypothyroid at the tissue level.

• Validated biomarkers of oxidative stress exist. None of them is in your standard blood panel.

  F2-isoprostanes, 8-hydroxy-2-deoxyguanosine, malondialdehyde, and the redox enzyme activities (SOD, GPx, catalase) are all validated biomarkers of oxidative stress with strong correlations to disease progression. They have been available in research settings for decades. None of them appears in the standard clinical panel. Ferritin and CRP, both accessible, give only indirect hints.

• Obesity is a condition of caloric excess and multiple simultaneous nutrient deficiencies

  Obese patients are among the most nutritionally deficient adults measured in modern populations. Vitamin D, folate, vitamin B12, iron, thiamine, magnesium, selenium, and vitamin A deficiencies are all documented at high prevalence in pre-bariatric assessment. The condition is not overnutrition. It is misnutrition.

• NAD+ declines with age, but not uniformly across tissues

  Human skin loses more than 50% of its NAD+ across adult life. Skeletal muscle drops roughly 10% per decade. Brain NAD+ shows a modest 10-25% decline from young adulthood to old age, with some recent studies finding no significant difference. The popular '50% decline' figure is accurate for skin. Extended to every tissue, it overstates what the measurements support.

• Trace lithium in drinking water is inversely associated with suicide mortality

  Two independent studies, one in 27 Texas counties (Schrauzer 1990) and one in 18 Japanese municipalities (Ohgami 2009), found that populations drinking water with higher trace lithium levels had significantly lower suicide rates. Subsequent meta-analyses have confirmed the association. Lithium is a nutrient before it is a medication, and its nutritional dose is 1,000-fold lower than the psychiatric dose.

• Glutathione is to the inside of cells what vitamin C is to the outside, and no ordinary blood panel measures it

  Glutathione is the most abundant intracellular antioxidant, the master regulator of cellular redox state, and central to detoxification, drug metabolism, and immune function. It is not measured in ordinary clinical care. Its role in cancer is context-dependent: essential in healthy cells for carcinogen clearance, elevated in tumor cells where it drives chemotherapy resistance.

• The dietary assessment methods nutritionists rely on under-report intake by roughly 25%

  24-hour recalls and food diaries, the two instruments most nutrition research relies on, under-report actual energy intake by 22 to 25% when validated against doubly labelled water. No known self-report instrument is unbiased. Yet the same instruments guide dietary policy, individual counseling, and clinical nutrient assessment.

• The chemical imbalance in the pitch was a hoax. The imbalances in the tissue are certain, and treatable.

  The chemical imbalance that sold four decades of antidepressants was overturned by a peer-reviewed umbrella review in 2022. The chemical imbalances that actually correlate with depression, anxiety, and bipolar disorder (omega-3, folate, B12, magnesium, vitamin D) are measurable in an ordinary blood draw, correctable with cheap intervention, and never named at the consultation.

• The standard serum B12 test is late, insensitive, and unspecific for deficiency

  Total serum B12 is a late, relatively insensitive and unspecific biomarker of deficiency. Its reported sensitivity across studies ranges from 13% to 75%. The functional markers (holotranscobalamin and methylmalonic acid) detect deficiency earlier and more reliably, and they are almost never ordered in first-line workup.

• More than 90% of Americans do not reach the vitamin E dietary reference

  More than 90% of Americans do not consume enough vitamin E to meet the estimated average requirement, and the circulating alpha-tocopherol test does not capture the deficit. This finding comes from Maret Traber, one of the researchers who helped set the reference in the first place.

• Thiamine deficiency is not a disease of the past — it is hiding in plain sight

  Thiamine deficiency is not a disease of the tropics or of alcoholism. It affects psychiatric patients, pregnant women, emergency department patients, diabetics, the elderly, dialysis patients, and children raised on ultra-processed food. No developed country has current data on how prevalent it is, because thiamine is not being measured.

• Riboflavin subclinical deficiency is widespread, including in high-income countries

  Subclinical riboflavin deficiency is much more widespread than official reports suggest, including in high-income countries, because the biomarkers are almost never measured. A Canadian survey found 40% biochemical deficiency in young women with theoretically adequate dietary intake.

• Human biology evolved on a potassium-to-sodium ratio of 10-to-1. Modern diets have inverted it.

  Before agriculture, humans consumed 6,000 to 11,000 mg of potassium per day and about 500 mg of sodium: a potassium-to-sodium ratio between 10:1 and 20:1. Every homeostatic mechanism we possess for sodium and potassium is calibrated to that ratio. Modern intakes have inverted it, and three decades of dietary guidance have not moved the median.

• No decline of aging predicts frailty better than muscle mass loss

  The single strongest predictor of impaired mobility, altered energy balance, and loss of vitality with age is the loss of muscle mass. It is rarely measured in routine primary care, even when the imaging tool that would measure it has already been ordered for something else.

• Subclinical magnesium deficiency is a public health crisis

  Subclinical magnesium deficiency increases the risk of numerous types of cardiovascular disease, costs nations around the world an incalculable amount in healthcare costs and suffering, and should be considered a public health crisis. Those are not campaign words. They are the words of a peer-reviewed 2018 paper in Open Heart.

• The standard blood test for magnesium misses more than 99% of it

  Less than 1% of the body's magnesium circulates in the blood. The remaining 99% is locked inside cells, bones, and muscles. Yet serum magnesium is the only magnesium test in most reference laboratories, and its reference ranges are known to be miscalibrated. An individual can be profoundly magnesium-deficient with a perfectly normal serum result.

• The most commonly missed nutritional deficiency in the industrialised world is iron

  Iron deficiency without anaemia is more common than iron deficiency anaemia in menstruating women. Its symptoms (fatigue, palpitations, hair thinning, brain fog, restless legs) are routinely attributed to almost anything else. Ferritin at 24 μg/L is flagged as normal against a reference range that begins at 10 or 15.

• Cardiovascular patients not identified with diabetes are simply undiagnosed

  The pathologist Joseph Kraft measured insulin curves in 15,000 patients across four decades. He found that people with cardiovascular disease who had not been identified as diabetic were, on his glucose-tolerance-plus-insulin test, hyperinsulinemic almost without exception. His conclusion was one line: they are not spared, they are undiagnosed.

• Choline is a required nutrient, and most people do not consume enough

  Choline is a required nutrient for humans: it must be consumed in the diet to maintain health. Yet current intakes for most people are well below the levels considered adequate. This finding comes from Steven Zeisel, the researcher whose work established choline's essentiality in the first place.

• More than seventy learned societies signed a 2022 declaration recognizing nutritional care as a human right, and almost no one outside hospital nutrition has heard of it

  On 5 September 2022, more than seventy national learned societies of clinical nutrition, from every continent, signed the Vienna Declaration on the Human Right to Nutritional Care. It formally recognizes access to nutritional care as a human right, intrinsically linked to the right to food and to health. Four years later, the text has barely left the hospital nutrition community.

• Creatine supplementation frees roughly half of your body's methyl budget

  Making creatine in your own body consumes 40 to 50 percent of the methyl groups your metabolism produces each day. Taking 3 to 5 grams of creatine as a supplement lets that budget go elsewhere: to DNA methylation, to phosphatidylcholine synthesis, to neurotransmitter production.