Can B12 help with sleep?

Whether vitamin B12 can improve sleep is not clearly supported by evidence. B12 is involved in circadian rhythm regulation and melatonin synthesis, and some small studies suggest a potential benefit for sleep disorders, especially in individuals with low B12 levels. However, the overall evidence is weak: most data come from observational or mechanistic studies, not from randomized controlled trials with sleep as a primary outcome. In people with normal B12 status, supplementation is unlikely to improve sleep. Deficiency can cause fatigue and neurological issues that indirectly affect sleep, and correcting a deficiency may help. The MyBody-X Women’s Wellness Check includes B12 measurement, but a test result alone does not indicate sleep quality. For sleep problems, consider other factors like stress, sleep hygiene, and hormonal balance. The evidence for B12 as a sleep aid is best described as 'unclear' – marketing claims should be viewed with caution.