Vitamin B12 (Cobalamin) & Vitamin C (Ascorbic Acid)

Caution Timing
Vitamin B12 (Cobalamin) → Vitamin C (Ascorbic Acid) →
Caution Timing

Very high-dose vitamin C may reduce vitamin B12 absorption.

Mechanism

Megadoses of vitamin C (>1000mg) taken simultaneously with B12 may convert some B12 to inactive analogs.

Recommendation

Take high-dose vitamin C and B12 supplements at least 2 hours apart. At normal doses, this is not a concern.

Sources

Tolerable upper intake limits

Reference values for safe daily intake of these supplements.

Vitamin C (Ascorbic Acid)
2000.000 mg
adults NIH ODS / IOM

High doses may cause diarrhea and GI distress.

All interactions Check your stack
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