Lifespan Nutrition

Bill Sardi Health Blog

  • Dietary Supplements Under Attack Again

    Rebuttal to:

    The vitamin epidemic: what is the evidence for harm or value?
    Internal Medicine Journal August 7, 2018


    Here we go again.  Another physician says there “no case for vitamin supplementation in normal, healthy, non-pregnant or lactating adults who are received the recommended daily intake of nutrients.”

    Here is my comment on each one of his criticisms of dietary supplementation.

    Vitamin A

    Vitamin Critic:  “Vitamin A Toxicity occurred in Antarctic and Arctic explorers who consumed the livers of seals, huskies or polar bears and can be fatal.  It is characterized by raised intracranial pressure, dermatitis, nausea and vomiting, double vision and convulsions.

    Rebuttal: Yes, we are talking about millions of units of vitamin A.  Let’s concede this point.  All consumers who are eating seal or polar bear liver should refrain from doing so.

    Vitamin Critic: Of particular concern are other data that have linked vitamin A to an 18% increased incidence of lung cancer in a study of 29,133 Finnish smokers who received either αtocopherol (vitamin E) 50 mg or βetacarotene 20 mg and a 28% increase of lung cancer in a similar study in 18,314 smokers, some of whom had also been exposed to asbestos.

    Rebuttal: Not this one again? This study was published in the New England Journal of Medicine just prior to passage of the 1994 Dietary Supplement Health & Education Act in an attempt to legislatively classify all dietary supplements as drugs.  Here (below) a chart from that study reveals the difference in lung cancer incidence was not 18% (a relative number) but less than 1% (in hard numbers).

    Chart: Lung Cancer Incidence

    Source: New England Journal Medicine 1994; 330:1029-1035

    And 18 years after this study was published it was revealed that excessive vitamin A supplementation via beta carotene (which converts to vitamin A in the body) impairs vitamin D blood levels and negates any reduction in lung cancer achieved by vitamin D supplementation.  Vitamin D supplements (sunshine in a pill) were found to reduce the risk of lung cancer in sun-deprived Finnish men, but not when they consumed excessive amount of vitamin A.  These Finnish men needed more vitamins, not less.

    Excessive beta carotene is shuttled to the skin to provide internal sun protection and is not toxic to the liver as is mega-dose vitamin A.  Most reports of liver toxicity from vitamin A supplementation emanate from alcoholics whose livers are compromised by their drinking habit.

    The Council For Responsible Nutrition (CRN) says: “the human data, however, are often confounded by other factors such as alcohol intake, infectious hepatitis, hepatotoxic drugs, and pre-existing liver disease. “

    According to a CRN report: Consumption of 25,000 to 50,000 IU of preformed vitamin A per day for periods of several months or more can produce multiple adverse effects, including liver toxicity; but the effects in this intake range may be dependent on compromised liver health or function. A supplemental intake of approximately 25,000 IU is the lowest dose at which such effect can be confidently attributed to vitamin A in persons with mildly or moderately compromised liver health.

    Vitamin critic: The vitamin critic (whose name shall remain unmentioned) warns consumers away from vitamin A supplements, saying: “the Upper Limit for both sexes is 3000 micrograms per day.”  He adds: “Particular care is needed not to exceed recommended doses in pregnancy because of the possibility of miscarriage and teratogenicity (birth defects).”

    Rebuttal: However, the Upper Limit (UL) is the perfectly safe upper limit, not the toxic limit.  The Institute of Medicine states “the No Observed Adverse Effects Level (NOAEL) of intake is 15,000 international units (IU) of vitamin A per day.”  “The lowest dose at which birth defects are observed is at least 25,000 IU/day.  There is a long history of safe use of dietary supplements containing 5,000, 8,000, and 10,000 IU per day,” says a CRN report.

    Vitamin critic: “Particular care is needed not to exceed recommended doses (of vitamin A) in pregnancy because of the possibility of miscarriage and birth defects.” 

    Rebuttal: The CRN states: a dose of 30,000 IU per day “should be considered as non-teratogenic (birth defects) in [humans]”

    Vitamin D

    Vitamin critic: At present there is no case for routine supplementation of vitamin D unless there is a clinical or biochemical indication.  The Upper Limit for both sexes is 80 micrograms/day (320 IU – international units).

    320 IU (international units) won’t even raise blood levels.  Thirty minutes of total body midday sunshine will produce ~10,000 units of vitamin C without side effects.

    This recommendation is in the face of an epidemic of sun-deprivation disorders.  A study recently showed children are only getting 7 hours of outdoor sunshine per week.

    An Institute of Medicine report indicates about one-quarter of the US population are at risk of vitamin D inadequacy and 8% are at risk of vitamin D deficiency (2001-06) This amounts to millions of people.

    Vitamin C

    Vitamin critic: High doses are definitely associated with adverse reactions so there does not seem to be any place for routine supplementation in healthy individuals.  RDI for both sexes is 45 mg/day without an UL.

    Rebuttal: It is inconceivable that a few milligram of vitamin C (~110 mgs per day) obtained from the diet can possibly compensate for a gene mutation that occurred long ago in human history that halted the internal production of vitamin C.  Prior to that gene mutation it is estimated humans endogenously produced 1800-4000 milligrams of vitamin C per day, and more when under physical or mental stress.

    The vitamin critic’s disclaimer is “There is no case for vitamin supplementation in normal, healthy, non‐pregnant or lactating adults who are receiving the recommended daily intake of nutrients.”  But how many are truly healthy?

    Diabetics have a higher need for vitamin C (100 million). Aspirin users (~50 million), users of certain drugs (steroids, sex hormones), smokers (38 million), alcohol abusers (16 million), face depletion of vitamin C.  Diuretics deplete vitamin C (~20 million) Growing children need more vitamin C.  Hospitalized patients need more vitamin C as do nursing home patients.  That amounts to over 200 million Americans out of a population of 325 million who are not likely to have adequate vitamin C intake from their diet and must rely upon dietary supplements.

    Vitamin critic: The vitamin critic says the Recommended Dietary Allowance (RDI) both sexes is 45 mg/day of vitamin C without an Upper Limit.  Public health authorities recommend 60-200 milligrams of supplemental vitamin C to maintain health. 

    Rebuttal: The perfectly safe Upper Limit is 2000 milligrams is often mischaracterized as the toxic upper limit.  Makers of vitamin C pills seem to know better and the lowest dose vitamin C pill on the market today provides 500 milligrams.

    Thiamine (vitamin B1)

    Vitamin critic: The vitamin critic says there are no indications for routine supplementation of vitamin B1. 

    Rebuttal: Derrick Lonsdale MD says high carbohydrate diets, sugary foods, block vitamin B1 absorption, a problem he calls “high calorie malnutrition.”  Alcohol, coffee, tea, also block B1 absorption.  The vitamin critic warns of side effects from high doses, but absorption is dose limited to 5 mg per day.  The body won’t absorb any more.

    Summary: The US Department of Agriculture publishes the percent of the US population with INADEQUATE INTAKE of essential nutrients.  It is worth reprinting here:

    US Department of Agriculture Adequate Nutrient Intake Data

    Source: US Dept. Agriculture


    (* see notes below)

    % US population with ADEQUATE intake % US population with INADEQUATE intake

    (number of Americans based on population of 314 million)

    Vitamin A 46.0% 54.0% (169 million)
    Vitamin C* 58.0% 42.0% (131 million)
    Vitamin E 13.6% 86.4% (271 million)
    Vitamin B1* (thiamin) 81.6% 18.4% (57 million)
    Vitamin B2 (riboflavin) 89.1% 10.9% (34 million)
    Vitamin B3 (niacin) 87.2% 12.8% (40 million)
    Vitamin B6 (pyridoxine) 73.9% 26.1% (82 million)
    Vitamin B9 (folic acid) 59.7 40.3% (126 million)
    Vitamin B12* (cobalamin) 79.7% 20.3% (63 million)
    Magnesium 43.0% 57.0% (179 million)
    Iron* 89.5% 10.5% (33 million)
    Selenium 91.5% 8.5% (26 million)
    Zinc* 70.8% 29.2% (91 million)
    Copper* 84.2% 15.8% (50 million)
    Calcium* 30.9% 69.1% (217 million)
    Potassium 7.6% 92.4% (290 million)

    Based upon the “Average Requirement.” Nutrient intakes are for individuals 2 year old and over, who completed Day-1 intakes for the 1999-2000, the 2001-2002, and the 2003-2004 WWEIA/NHANES.



    Vitamin C: Virtually no one except supplement users maintain adequate vitamin C levels due to rapid excretion of this water soluble vitamin; requires repeated doses throughout the day for optimal blood concentration (500 mg 5X/day)

    Vitamin B1 (thiamin): indicates intake only; refined sugars, alcohol, coffee, tea, drugs block absorption. Massively larger numbers are deficient.

    Vitamin B12 (cobalamin): supplementation often resolves symptoms of fatigue and neuritis (tingling, numbness) even when blood levels are adequate, indicating commonly-occurring blood concentration (reference range) is not adequate and therapeutic doses (above RDA) are required.

    Iron: anemic individuals are largely comprised of young menstruating females. Some individuals with chronic inflammation, infection or malignancy.

    Zinc: Various medications (diuretics, estrogen, beta-blockers, ACE inhibitors) deplete zinc. This mineral is often poorly absorbed due to lack of stomach acid (52% of Americans have H pylori infection that inhibits secretion of stomach acid). Larger numbers are deficient than estimated above.