Can you take Vitamin C and Vitamin B12 together?
At doses above 500 mg, Vitamin C can convert some B12 into inactive forms. Separating them by two hours or using methylcobalamin avoids the issue.
Severity
Caution
Evidence
moderate
Timing
Separate by 2+ hours, or use methylcobalamin.
How it works
Ascorbic acid can reduce cyanocobalamin to inactive analogues in the gut through a chemical reaction.
The degradation is more pronounced with cyanocobalamin than methylcobalamin. At standard Vitamin C doses (100–250 mg), the effect is minimal. It becomes a concern above 500 mg taken simultaneously with B12.
What to do
Take B12 in the morning and Vitamin C later in the day. Alternatively, switch to methylcobalamin, which is less vulnerable to this reaction.
Frequently asked
Should I separate Vitamin C and Vitamin B12?
Consider separating them. Separate by 2+ hours, or use methylcobalamin. Consult a healthcare professional for personalised advice.
Why do Vitamin C and Vitamin B12 interact?
Ascorbic acid can reduce cyanocobalamin to inactive analogues in the gut through a chemical reaction.
How strong is the evidence for this interaction?
The evidence is moderate. Some studies support this interaction, but more research may be needed.
About these supplements
Other Vitamin C interactions
Other Vitamin B12 interactions
Check your full stack
for interactions.
See what competes, what combines well, and when to take everything. Every interaction cites a published source.
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1 flagZinc and Iron compete for the same absorption pathway. Take at least 2 hours apart.
Supplements
This information is for educational purposes only. It is not medical advice and does not diagnose, treat, cure, or prevent any disease. Always consult a qualified healthcare professional.