vitamin c
10 interactions related to vitamin c
vitamin c + iron
Vitamin c enhances absorption of non-heme iron from supplements and plant foods, a beneficial nutrient synergy, though the real-world benefit across a full diet is usually modest.
smoking + vitamin c
Smoking increases oxidative stress and accelerates the body's turnover of vitamin C, leaving smokers with consistently lower blood and tissue levels of ascorbic acid than non-smokers eating the same diet. Because of this, expert nutrition bodies recommend that people who smoke aim for a higher daily vitamin C intake than non-smokers.
vitamin e + vitamin c
Vitamin C regenerates the active form of vitamin E. After vitamin E neutralizes a lipid free radical and becomes a tocopheroxyl radical, vitamin C donates an electron at the membrane surface to restore it. This recycling loop extends antioxidant capacity at the lipid-water interface of cell membranes. It is a beneficial synergy, not a risk.
glutathione + vitamin c
Glutathione and vitamin C participate in the same cellular antioxidant network and help regenerate one another. When vitamin C is oxidised to dehydroascorbate, glutathione donates electrons to convert it back to active ascorbate; in turn, vitamin C helps keep glutathione in its active reduced form. The two are commonly supplemented together and the combination is well tolerated, though clinical benefit beyond the established biochemistry is modest and not consistently proven.
nac + vitamin c
NAC and vitamin C touch the same antioxidant network on paper, but the human evidence for taking them together is mixed: a controlled trial found the combination raised oxidative stress and tissue-damage markers after acute muscle injury rather than protecting against them.
zinc + vitamin c
Zinc and vitamin C act on complementary arms of the immune system: zinc supports T-cell, B-cell, and natural killer cell function and can interfere with rhinovirus replication in the throat, while vitamin C supports white blood cell function and maintains skin and mucosal barriers. Taken together, the pair may modestly shorten and ease common cold symptoms when started early, though the human evidence for the combination specifically is limited.
collagen + vitamin c
Vitamin C is a required cofactor for prolyl and lysyl hydroxylase, the enzymes that hydroxylate proline and lysine residues during collagen synthesis and stabilize the triple-helix structure. Taking collagen peptides (or gelatin) together with a source of vitamin C supplies both the amino acid building blocks and the enzymatic cofactor the body needs to assemble functional new collagen. This is a benign nutritional synergy, not a risk.
vitamin c + glucose meter
Vitamin C (ascorbic acid) is a strong reducing agent that can interfere with the chemistry used by many fingerstick and bedside glucose meters, producing falsely high blood glucose readings. This is most likely with high-dose oral or intravenous vitamin C. Published case reports describe patients on high-dose IV vitamin C being misdiagnosed with diabetic ketoacidosis and given inappropriate insulin, leading to dangerous hypoglycemia.
vitamin c + quercetin
Quercetin is a plant flavonoid with antioxidant and anti-inflammatory activity. As quercetin scavenges free radicals it becomes oxidized, and vitamin C can donate electrons to recycle it back to its active form, theoretically prolonging its effect and limiting prooxidant byproducts. This pairing is popular for immune and allergy support, but the human evidence is limited and largely mechanistic.
vitamin c + stool occult blood test
Vitamin C (ascorbic acid) is a reducing agent that can block the guaiac peroxidase color reaction used in traditional guaiac-based fecal occult blood tests (gFOBT, including Hemoccult). This can produce a falsely negative result even when gastrointestinal bleeding is present, potentially masking a bleeding source. Newer fecal immunochemical tests (FIT) use antibodies to detect human hemoglobin and are not affected.