Can You Take Melatonin with Vitamin B12?

Taking melatonin and vitamin B12 together may affect how your body responds to light, potentially altering your sleep-wake cycle. This interaction could be important for people who are exposed to bright light at unusual times. Vitamin B12 may make your body's internal clock more sensitive to light. Vitamin B12 may interact with the effect of light on melatonin levels by changing the sensitivity of the suprachiasmatic nucleus, the part of the brain that regulates the circadian rhythm. This can affect how melatonin is suppressed by light. Essentially, vitamin B12 may make the body's internal clock more responsive to light.