FoundMyFitness · 2020-05-13 · Rhonda Patrick (host)
Vitamin C: Oral vs. Intravenous, Immune Effects, Cancer, Exercise Adaptation & More
75 claims checked against research: 4 contradicted 4 overstated 7 needing context 50 supported 10 unverified
10 No source found (not proven false)
Of more than 950 beef items listed in the USDA Food and Nutrition database, only 21 items contain any vitamin C.
"In fact, of more than 950 beef items listed in the USDA's Food and Nutrition database, only 21 items contain any vitamin C at all, and most contain tiny amounts that would be lost in cooking." (said at 0:09:44)
No published record matching the specific claim regarding the exact count of beef items (21 out of >950) containing vitamin C in the USDA Food and Nutrition database was located; this does not prove the claim false.
Alcohol consumption increases urinary vitamin C losses by nearly 50%.
"Alcohol consumption increases urinary vitamin C losses by nearly 50%, so higher intake might be needed to prevent deficiency." (said at 0:11:46)
No published record matching the claim that alcohol consumption increases urinary vitamin C losses by nearly 50% was located; this does not prove the claim false. While chronic alcohol use is clinically associated with poor micronutrient status and altered antioxidant metabolism, a specific quantifiable increase of approximately 50% in urinary ascorbic acid excretion following alcohol intake is not documented in the indexed literature.
Features of scurvy appear in as little as three months of vitamin C depletion.
"These early features of scurvy show up in as little as three months of vitamin C depletion, which is why sailors who were often at sea for long periods without access to fresh fruits and vegetables often developed scurvy." (said at 0:13:30)
No published record matching the claim that features of scurvy appear in as little as three months of vitamin C depletion was located; this does not prove the claim false.
Dehydroascorbic acid undergoes intracellular recycling back to ascorbate approximately four times per vitamin C molecule.
"Dehydroascorbic acid undergoes frequent intracellular recycling back to the reduced state. This cycle happens about four times for every vitamin C molecule." (said at 0:14:30)
No published record matching the specific claim that dehydroascorbic acid undergoes intracellular recycling back to ascorbate approximately four times per vitamin C molecule was located; this does not prove the claim false. While intracellular reduction and recycling of dehydroascorbic acid back to ascorbic acid is a well-established biochemical process (mediated by glutathione, thioredoxin reductase, and enzymatic dehydroascorbate reductases), no scientific literature establishes a fixed or average metric of "about four times" per molecule.
A 2-person study showed that 20 grams of liposomal vitamin C increased peak plasma levels to approximately 320 micromoles per liter, and a 36-gram dose increased levels to 400 micromoles per liter.
"There aren't tons of studies along these lines, but a very small single-blinded study with just two people showed that liposomal vitamin C dramatically increased plasma levels in a dose-dependent manner. Whereas 20 grams of liposomal vitamin C increased peak plasma levels to approximately 320 micromoles per liter of blood, a 36-gram liposomal dose increased levels to 400 micromoles per liter." (said at 0:18:58)
No published record matching the 2-person pharmacokinetic study reporting peak plasma vitamin C levels of approximately 320 µmol/L after a 20 g liposomal dose and 400 µmol/L after a 36 g liposomal dose was located in indexed medical databases; this does not prove the claim false.
Neutrophils and leukocytes have roughly 50 to 100 times higher vitamin C concentrations than blood plasma.
"Vitamin C is highly concentrated in immune cells, with neutrophils and leukocytes having roughly 50 to 100 times higher vitamin C concentrations than plasma." (said at 0:21:33)
No published record matching the claim that neutrophils and leukocytes have roughly 50 to 100 times higher vitamin C concentrations than blood plasma was located; this does not prove the claim false.
In a study of 41 asthma patients, daily supplementation with 1 gram of vitamin C for 14 weeks resulted in fewer and less severe asthma attacks compared to placebo.
"One study involved 41 asthma patients whose average age was 26 years old. The patients took 1 gram of vitamin C or a placebo daily for 14 weeks. The patients who took vitamin C had fewer, less severe asthma attacks compared to the placebo group." (said at 0:33:46)
No published record matching the specific study described—a 14-week randomized trial of 41 asthma patients with an average age of 26 years taking 1 gram of vitamin C daily resulting in fewer and less severe asthma attacks—was located; this does not prove the claim false. Systematic reviews of randomized controlled trials evaluating vitamin C for asthma, including Cochrane reviews, have found insufficient and inconclusive evidence to support routine supplementation for reducing asthma attacks or symptoms. [WARNING: a cited paper has been RETRACTED]
The search did find related studies, but none that directly tests this claim:
In a study of 11 female rheumatoid arthritis patients aged 45 to 69, intravenous vitamin C treatment decreased C-reactive protein levels by 44% compared to baseline.
"A study involving 11 female patients between the ages of 45 and 69 years who were diagnosed with rheumatoid arthritis and had been given intravenous vitamin C for varying durations found that women's C-reactive protein levels decreased 44% compared to levels before treatment." (said at 1:02:02)
No published record matching the claim that a study of 11 female rheumatoid arthritis patients aged 45 to 69 treated with intravenous vitamin C experienced a 44% decrease in C-reactive protein levels was located in indexed medical databases; this does not prove the claim false.
Repeated treatments with high-dose intravenous vitamin C do not increase pro-oxidative markers in healthy individuals.
"It's important to know that successive treatments with high-dose intravenous vitamin C do not increase pro-oxidative markers in healthy people, suggesting that normal cells aren't damaged by the burst of hydrogen peroxide produced by the intravenous vitamin C." (said at 1:06:40)
No published record matching the claim that successive or repeated treatments with high-dose intravenous vitamin C do not increase pro-oxidative markers in healthy individuals was located; this does not prove the claim false.
A prospective cohort study of over 48,000 Swedish men found an annual kidney stone risk of 0.16% in non-supplementers versus 0.3% in vitamin C supplementers (1 stone per 613 years vs 1 stone per 323 years).
"Another prospective cohort study in more than 48,000 Swedish men found that the men's risk of developing kidney stones was 0.16% per year among men who did not supplement, but was 0.3% per year among those who did, which is a statistical difference with no clinical significance. In other words, a person in this study who supplemented with vitamin C can expect a kidney stone every 323 years, whereas a person who did not supplement with vitamin C can expect a kidney stone every 613 years." (said at 1:12:51)
No published record matching the claim that a prospective cohort study of over 48,000 Swedish men found an annual kidney stone incidence of 0.16% in non-supplementers versus 0.3% in vitamin C supplementers (1 stone per 613 years vs 1 stone per 323 years) was located; this does not prove the claim false.
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.