Is there a study out there that links vitamin B12 specifically with lowered or raised melatonin? And related to that, is there any relation to high amounts of B12, and lack of sleep or other sleep issues? I take B12, as a vegetarian, as I am reported to be deficient, but when I take a full recommended dose (as opposed to half) it seems to be interfering with my sleep. As I am melatonin sensitive, I am exploring a link.

I had been sleeping fine all along with a mild vitamin deficiency, dropping off to sleep within a minute or so after hitting the pillow. The nights after the days where I took a full dose of B12, I was up for hours past my bedtime in hyper alert mode. No caffeine was taken those days.

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    When I had borderline B12 deficiency my brain seemed to forget how to sleep at all. I don't see it in symptom lists much, but it was the only symptom I had.
    – Zanna
    Apr 30, 2017 at 5:05

1 Answer 1


Those who can't get to sleep at night may need vitamin B12. Studies show that B12 causes an earlier release of melatonin at night which resets the sleep-wake cycle. (Melatonin has been called "the sleep hormone" because of its effects on sleep). B12 acts directly on the pineal gland to provoke a faster release of melatonin. At the tail end, B12 causes melatonin to drop off faster. B12 helps you get to sleep earlier, and may help you wake up earlier if you leave a curtain open to the morning sun. B12 sensitizes you to morning light, which helps you wake up. Very serious sleep-wake disorders have been successfully treated with vitamin B12 in the methylcobalamin form, although it may not work for everyone. Unfortunately, the vitamin doesn't help people who want to cut down on their sleep time altogether.


A summary of the study from someone's blog

However, before looking into your question I had no idea B12 could help with sleep, as it is an ingredient in most energy drinks and a prevalent ingredient in many energy shots

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    While the percentages are high, that indicates the amount relative to the recommended daily allowance, not relative to other ingredients in energy drinks. (That being said, it's clearly present in energy drinks.)
    – Erica
    Apr 30, 2017 at 16:32
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    Thank you @chiliNUT, I think you're on to something. The B12 I was taking was over 1000% of the daily recommended value. I had no idea this was also in these energy drinks. Very helpful info. Thanks everyone! May 1, 2017 at 12:28
  • @Erica I didn't think of that, that makes sense, I'm not sure if the volumes are comparable but the energy blend is 3,740x the volume of the B12
    – chiliNUT
    May 1, 2017 at 15:33

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