G6PD deficiency: why skip high-dose vitamin C
Megadose vitamin C gets sold as a harmless health habit. If you carry a G6PD variant, it isn't.
G6PD is an enzyme that keeps your red blood cells from getting wrecked by oxidative stress. When it's in short supply, that protection fails, and strong oxidants can make red cells break apart. The medical name for that is hemolysis. The gene sits on the X chromosome, which is why men get hit hardest. High-dose vitamin C is one of the more common triggers, and one of the easiest to avoid.
You carry a G6PD-deficiency variant. With this variant, high-dose vitamin C and other strong oxidants can make your red blood cells break apart, which is called hemolysis. Keep vitamin C to normal food and RDA amounts. This hits men hardest, since they only have one X copy and no second gene to fall back on. Treat it as a flag to act on, not a diagnosis. A doctor can confirm your G6PD status with a simple blood test.
PubMed 38898838 · G6PD deficiency & vitamin C hemolysis
You carry the G6PD Mediterranean variant, which is one of the more severe forms of the deficiency. High-dose vitamin C and other strong oxidants can break your red blood cells apart, and so can fava beans and certain drugs. Keep vitamin C to normal food amounts. This hits men hardest, since they only have one X copy and no second gene to fall back on. Treat it as a flag to act on, not a diagnosis. A doctor can confirm your G6PD status with a simple blood test.
PubMed 38898838 · G6PD deficiency & vitamin C hemolysis
What G6PD does
The rule here is short. Keep vitamin C to normal food and RDA levels, and remember that fava beans and a handful of medications are the other classic triggers in G6PD deficiency.
This is a heads-up, not a diagnosis. A doctor can confirm where you actually stand with a simple blood test. It matters most for men, who only carry one copy of the X chromosome and have no backup.
Your variants, decoded
One of the most common deficiency variants, seen mostly in people of African ancestry.
| CC | Typical. No deficiency variant here. |
| CT | One copy. Carries the variant; play it safe with strong oxidants. |
| TT | Deficiency variant present. Skip high-dose oxidants. |
A harsher form of the deficiency than the A- variant.
| GG | Typical. No deficiency variant here. |
| GA | One copy of the Mediterranean variant; be cautious. |
| AA | Mediterranean deficiency. Tighter avoidance than the milder forms. |
Genotypes are shown order-insensitively and on the forward strand; your own export may print the complementary letters — the meaning is the same.
See this matched to your own DNA — free.
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Questions
Can I take vitamin C with G6PD deficiency?
Normal amounts from food are usually fine. The problem is high-dose or IV vitamin C, plus other strong oxidants, which can set off hemolysis. Check your status with a clinician before you assume anything.