Does Vitamin B12 Keep You Awake At Night?

What is B12?

Vitamin B12, otherwise known as cobalamin, is essential for our well-being. It is a nutrient that our body needs so that it can perform certain processes such as energy and red blood cell production, as well as DNA synthesis. 

Vitamin B12 is one of the most structurally complex vitamins that we know of. Although it is a vitamin that is found in many foods, B12 deficiency is relatively common. 

There are several causes for vitamin B12 deficiency: malabsorption, certain medical conditions, B12-depleting medications, or simply because you are not eating enough of the foods that are rich in vitamin B12. 

It has been demonstrated that low levels of vitamin B12 are linked to a number of health conditions such as dementia, depression, and osteoporosis, among others. However, a deficiency in vitamin B12 most commonly leads to more minor health issues, such as anaemia.

Signs of B12 deficiency

A deficiency in B12 can cause a wide array of symptoms. These symptoms most commonly develop gradually and worsen as time goes on. The signs of a B12 deficiency include:1 

  • Fatigue 
  • A sore, red tongue and frequent mouth ulcers
  • Frequent pins and needles
  • A pale yellow hue to your skin
  • Irritability and depression
  • A general decline in mental and cognitive abilities, such as memory

In addition to the symptoms mentioned above you may also experience muscle cramps, weakness, and disturbances in vision. 

Health conditions linked to low levels of B12

Certain individuals are at an increased risk of vitamin B12 deficiency. For example, vegans or people who frequently take medications such as antacids and B12-depleting medications are at a higher risk of developing a B12 deficiency. There are also health conditions that put you at risk of having lower levels of B12, such as Crohn's disease or autoimmune diseases.

How B12 and energy levels are connected

Vitamin B12 is essential for the overall healthy functioning of the body. It is one of the eight B vitamins that help convert complex carbohydrates from our food into glucose, which supplies our body with the energy it needs for the day.2 Therefore, if you are not getting enough B12 from your diet, you may experience low energy levels. 

Can vitamin B12 prevent insomnia?

Our diets have a profound effect on our wellbeing. Vitamin B12 plays a critical role in our daily functioning; low levels of vitamin B12 have been linked with fatigue and depression, but is there a link between vitamin B12 and insomnia?

It has been shown that certain vitamins work directly on the brain to help bring on sleep. Vitamin B12 is one such vitamin that helps people with sleep disorders such as insomnia.3 In fact, it has been shown to improve the quality of sleep in healthy individuals who consistently take a prescribed dose. 

The link between B12 and improved sleep quality is still being studied. However, scientists believe that it is because vitamin B12 serves as a circadian modulator of the sleep hormone, melatonin, meaning it aids in its production.


A vitamin B12 deficiency can cause a host of symptoms. While it is usually harmless, low levels of B12 have been linked to several health conditions and can affect general overall well-being. You should consult your doctor if you are experiencing symptoms that you think could be caused by a B12 deficiency - it can be easily diagnosed based on your symptoms and the results of a simple blood test.


  1. Shipton MJ, Thachil J. Vitamin B12 deficiency - A 21st-century perspective . Clin Med (Lond). 2015;15(2):145-150. doi:10.7861/clinmedicine.15-2-145.
  2. Kennedy DO. B Vitamins and the Brain: Mechanisms, Dose and Efficacy--A Review. Nutrients. 2016;8(2):68. Published 2016 Jan 27.
  3. Behrooz K. Vitamin B12 and Circadian Rhythm Sleep Disorders: Patient Treatments vs. Controlled Studies. Journal of Sleep Disorders and Management. 2019;5.
This content is purely informational and isn’t medical guidance. It shouldn’t replace professional medical counsel. Always consult your physician regarding treatment risks and benefits. See our editorial standards for more details.

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Imogen Scott

Postgraduate Degree, Neuroscience, Goldsmiths, University of London

Imogen Scott, based in London, is deeply rooted in mental health and healthcare. Serving as an Account Executive at Silver Buck, she emphasizes digital health innovations. Previously, she showcased her commitment as a Medical Writer Intern at Klarity and supported students with special needs at Charlton Park Academy. With a Bachelor's in Psychology and an ongoing Neuroscience postgrad from Goldsmiths, Imogen is a blend of academic and professional passion in health.

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