Can Vitamins Make You Sleepy?

Vitamins are used by many people all over the world to improve and maintain their health, boost immunity, and protect against micronutrient deficiencies. Although a healthy diet can provide all of these advantages, vitamin supplements can also be beneficial. Many other people take vitamins to help them sleep. 

A good night's sleep is undeniably beneficial to one's health, but can taking vitamins make you sleepy?

Certain vitamins deficiency or overdoses can cause fatigue and sleeplessness. The type of vitamin and the dosage determine this. This article discusses the effects of various vitamins that can cause sleepiness, as well as how to deal with fatigue in general.

List of vitamins that can make you sleepy

Some vitamins, more than others, are thought to make you sleepy. An exploratory study on vitamins and sleep found that vitamin and mineral intake or lack of these substances may affect sleep.¹

The following is a list of vitamins that can help you sleep and rest well:

  • Vitamin A
  • Vitamin B (B3, B6, B9 B12)
  • Vitamin C
  • Vitamin D
  • Vitamin E
  • Multivitamins (i.e. a combination of all or some vitamins plus certain minerals such as Iron, Calcium, Magnesium, Selenium e.t.c.)

Can taking too many vitamins make you sleepy?

They are taking too many vitamins results in overdosage, which can have serious consequences in the short or long term. Excessive vitamin consumption can cause extreme fatigue, weakness, nausea, vomiting, bone mass loss, and depression. These negative effects vary according to the type of vitamins consumed. 

When taking vitamins, it is best to stick to the recommended or prescribed dosage to get the best results and avoid side effects. Each vitamin has a recommended daily intake; for more information, click here.

Is it better to take vitamins in the morning or at night?

There is no right or wrong answer when it comes to taking vitamins in the morning or at night. Some people believe that taking vitamins in the morning is better because it energizes you for the day ahead, while others believe that taking vitamins at night helps you relax and prepare for bed. 

Ultimately, the best time to take vitamins is determined by the vitamin and the health benefits you seek. 

The table below gives you a general idea of when to take your vitamins.

Some B vitamins such as Vitamin B6 and B12Vitamin B3
Vitamin CCertain minerals, for example, magnesium. 
Vitamin D

Because there is no research to support the best time to consume vitamins A, E, and K, they can be taken at any time of day.

Effects of vitamins on Sleep

According to research, vitamin and nutrient deficiencies can affect your sleep pattern, and making good nutrient choices can improve your sleep rhythm.²  There is a growing interest in the science community in the association of various vitamins and sleep. 

Better sleep has been linked to better nutritional status for vitamins E, C, folate, vitamin B12, a group of carotenoids (type of plant-based vitamin A), and vitamin D, according to research.³

Below is a list of vitamins and how each of these vitamins affects your sleep. 

Vitamin A 

Apart from vitamin A role in maintaining your vision, organs, and reproductive system, this vitamin is also responsible for setting our sleep rhythm. This means that vitamin A is essential for helping us have a good night's sleep, stay asleep for an adequate amount of time, feel rested when we wake up, and fight fatigue.

Scientific evidence shows that people with lower vitamin A levels are more likely to suffer from sleep disorders.³

Consume vitamin A-rich foods like red bell pepper, milk, and liver. Before taking vitamin A supplements to improve your sleep, consult your doctor.

B vitamins

  • Vitamin B6: asides from its role in cognitive development and immune system support, vitamin B6 also aids sleep. Vitamin B6 promotes the production of the hormones serotonin and melatonin, both of which are essential for restful sleep and mood regulation. This vitamin deficiency has been linked to insomnia and depression. Vitamin B6 is abundant in milk, eggs, and bananas. To improve your sleep and overall health, consume vitamin B6-rich foods
  • Vitamin B9 (Folate/Folic acid): Folate, also known as folic acid, is required for red blood cell formation, cell growth, and the prevention of birth defects. Another important advantage of this vitamin is its ability to reverse sleep deprivation. A study of two groups of test subjects concluded that folic acid supplementation is effective in combating sleep deprivation. It is important to consult a doctor before taking folic acid supplements. An overdose can have negative health consequences
  • Vitamin B12: this vitamin is well-known for its role in brain development and functioning, as well as red blood cell formation. Vitamin B12 also contributes to the production of melatonin, a hormone that regulates our sleep-wake cycle Vitamin B12 deficiency causes extreme fatigue and, in some cases, insomnia. To obtain the recommended daily intake, consuming vitamin-rich foods such as eggs, meat, fish and dairy products or supplements is essential

Other B vitamin groups are also required to improve sleep duration and quality.

Vitamin C

There is a good chance that you have enough vitamin C if you get enough sleep. Vitamin C can help you sleep better by increasing the length of your sleep and lowering your risk of sleep apnea, a condition in which your breathing repeatedly stops and restarts while you sleep.

Several studies suggest that vitamin C may help improve sleep quality and duration. According to a 2013 study, people who consumed enough vitamin C had better sleep quality than those who consumed less. 

If you have difficulty sleeping, you may be deficient in vitamin C. Include citrus fruits in your diet, as well as green leafy vegetables and other nutrient-rich foods, or take vitamin C supplements.

Vitamin D 

Several studies have linked vitamin D deficiency to sleep problems such as disruption, insomnia, and poor sleep quality. Vitamin D, also known as the "sunshine vitamin," aids in producing melatonin.

According to a 2022 study, Vitamin D has both a direct and indirect role in the regulation of sleep. Despite vitamin D deficiency is linked to sleep disorders, there is still insufficient evidence to support the role of vitamin D supplementation in the prevention or treatment of sleep disorders.

Consume oil fish, egg yolks, and other vitamin D-fortified foods to increase your vitamin D levels. Get enough sunlight as well, or take vitamin D supplements.

Vitamin E

Vitamin E is an effective antioxidant that aids in cell and immune system protection. Along with the advantages it provides to our cells, vitamin E aids in the improvement of sleep and the treatment of sleep-related issues.  

There is evidence that vitamin E protects against memory loss caused by sleep deprivation.  The study discovered that vitamin E reduced memory loss in test subjects who were sleep deprived. 

Studies have also shown that combining vitamin E and vitamin C can improve sleep quality and address breathing issues in people with sleep apnea.

Try to consume almonds, broccoli, spinach, and other nutrient-dense foods to boost your vitamin E levels. Vitamin E supplements are also recommended; however, consult your doctor before taking any. 

How much can you take in per vitamin?

Based on certain criteria, the NHS established guidelines for how much of each vitamin and mineral you can consume in a day. Click here for more information.

Please keep in mind that this list does not apply to children or pregnant or breastfeeding women, as their recommended requirements differ.

Figuring out fatigue

Fatigue refers to extreme tiredness caused by stress, a lack of sleep, or other lifestyle factors. Long-term fatigue can increase your risk factors for serious health conditions such as anxiety disorders, anaemia, and chronic fatigue syndrome. 

Aside from taking dietary/vitamin supplements, there are a number of other ways to combat fatigue and induce sleep. These are some examples:

  • Physical activity; engage in physical activities such as walking, yoga, swimming, and a variety of other exercises. According to a John Hopkins study, exercising helps you fall asleep faster, improves your sleep quality, and lowers your risk of insomnia. Aside from improving your sleep rhythm, exercise also aids in the production of melatonin, a hormone that plays a role in managing your sleep-wake cycles. Before you go to bed tonight, try a quick workout
  • Medication; people suffering from severe fatigue frequently take medication, either over-the-counter or prescribed. Before purchasing any type of medication, consult with your doctor
  • Make relaxing activities a part of your daily routine. Listen to music, read a book, or perform stress-relieving exercises
  • Reduce or eliminate caffeine consumption; anyone experiencing fatigue should reduce or eliminate caffeine from their diet. Try abstaining from caffeine for a month to see if you feel less tired without it
  • Do not overeat before going to bed. This would make you feel very heavy and you may experience bloating or acid reflux which will affect your sleep
  • Modify your diet; one of the causes of extreme fatigue is iron deficiency. When you are iron deficient, your body cannot produce enough red blood cells to carry oxygen, leaving you weak and tired. A diet high in vitamin C can help with iron absorption in the body. To combat fatigue, it is also advised to consume vitamin-rich foods and take other supplements such as vitamin D and folic acid


Vitamins can help with sleep issues and fatigue in general. If you have trouble sleeping, you may be lacking in one or more of the vitamins listed above. It's always a good idea to consult your doctor before taking supplements to ensure you're getting the right amount and avoiding vitamin toxicity. Engage in physical and relaxing activities and make better lifestyle choices; these strategies will help you deal with fatigue.


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  2. How that Late-night Snack Affects your Sleep [Internet]. NBC News. [cited 2022 Oct 20]. Available from:
  3. Beydoun MA, Gamaldo AA, Canas JA, Beydoun HA, Shah MT, McNeely JM, et al. Serum Nutritional Biomarkers and their Associations with Sleep among US adults in recent national surveys. PLoS One. 2014;9(8):e103490.
  4. Zadeh SS, Begum K. Comparison of Nutrient Intake by Sleep Status in Selected Adults in Mysore, India. Nutr Res Pract [Internet]. 2011 Jun 21 [cited 2022 Oct 20];5(3):230–5. Available from:
  5. Zhang X, Wang Y, Zhao R, Hu X, Zhang B, Lv X, et al. Folic Acid Supplementation Suppresses Sleep Deprivation-induced Telomere Dysfunction and Senescence-associated Secretory Phenotype(Sasp). Oxid Med Cell Longev. 2019;2019:4569614.
  6. Grandner MA, Jackson N, Gerstner JR, Knutson KL. Dietary Nutrients Associated with Short and Long Sleep Duration. Data from a Nationally Representative Sample. Appetite [Internet]. 2013 May [cited 2022 Oct 20];64:71–80. Available from:
  7. Romano F, Muscogiuri G, Di Benedetto E, Zhukouskaya VV, Barrea L, Savastano S, et al. Vitamin D and Sleep Regulation: Is There A Role for Vitamin D? Curr Pharm Des. 2020;26(21):2492–6.
  8. Alzoubi KH, Khabour OF, Rashid BA, Damaj IM, Salah HA. The Neuroprotective Effect of Vitamin E on Chronic Sleep Deprivation-induced Memory Impairment: The Role of Oxidative Stress. Behavioural Brain Research [Internet]. 2012 Jan 1 [cited 2022 Oct 20];226(1):205–10. Available from:
  9. Singh TD, Patial K, Vijayan VK, Ravi K. Oxidative Stress and Obstructive Sleep Apnoea Syndrome. Indian J Chest Dis Allied Sci. 2009 Dec;51(4):217–24.
  10. Exercising for Better Sleep [Internet]. 2021 [cited 2022 Oct 20]. Available from: 
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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Amanda Yad-El Ugboji

Bachelors of science Public- Bsc Public health, Babcock University, Nigeria

Amanda is a public health entrepreneur and content creator with a strong passion for health communications.
She enjoys using her skills to contribute to projects aiming for sustainable health for all and equity. Related to this, Amanda is passionate about public health education.
She has two years of experience as a freelance writer, and her other skills include writing, blogging and public speaking."

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