From the FDA Drug Label
The FDA drug label does not answer the question.
From the Research
The best time to take vitamin B12 supplements is in the morning with breakfast, as taking B12 with food helps improve absorption, particularly foods containing protein. According to a recent study published in 2024 1, oral vitamin B12 supplementation at a dosage of 1000 μg/d has been shown to improve vitamin B12 deficiency in pernicious anemia. This study found that 88.5% of patients were no longer deficient in vitamin B12 after 1 month of oral vitamin B12 supplementation, with significant improvement of plasma vitamin B12, plasma homocysteine, and plasma methylmalonic acid concentrations.
When considering the timing of vitamin B12 supplementation, it's essential to note that high-dose supplements (typically 1,000-2,000 mcg) can be taken on an empty stomach, as high doses can overcome absorption limitations 2. However, for those using B12 for energy, morning consumption is ideal to avoid potential sleep disruption. The typical recommended daily allowance for adults is 2.4 mcg, though supplements often contain much higher amounts since absorption rates decrease with higher doses.
It's also crucial to separate B12 from calcium supplements and certain antibiotics by at least two hours, as these can interfere with absorption 3. Vitamin B12 is water-soluble, so the body will only absorb what it needs and excrete the rest, making it generally safe to take at any time of day if morning doesn't work with the schedule. Key points to consider when taking vitamin B12 supplements include:
- Taking B12 with food, especially protein, to improve absorption
- High-dose supplements can be taken on an empty stomach
- Separating B12 from calcium supplements and certain antibiotics by at least two hours
- Vitamin B12 is water-soluble, making it safe to take at any time of day.