Excessive sleep (hypersomnia) is often linked to fatigue, and deficiencies in Vitamin D, B12, Iron, Magnesium, Folate (B9), and Vitamin C are common culprits, disrupting energy and sleep cycles. While you might not be lacking vitamins because you sleep too much, low levels of these nutrients can cause extreme tiredness, leading you to sleep excessively, so addressing them with diet or supplements (under medical advice) might help regulate your sleep patterns.
Vitamin and mineral deficiencies, including B2, B3, B5, B6, B9, B12, C, D, iron, and magnesium, are among the most common causes of unexplained fatigue. Vitamin D deficiencies affect over 50% of the global population, and approximately 12.5% have iron deficiency anemia.
Vitamin B12 deficiency: A rare cause of excessive daytime sleepiness. Journal of Clinical Sleep Medicine, 15(9), 1365–1367. National Institutes of Health.
The new research by McCarty et al. titled “Vitamin D, Race, and Excessive Daytime Sleepiness” was very interesting as well as somewhat confusing. The authors reported that more than half of their patients with somatic pain and sleep disruption had vitamin D deficiency.
Vitamin B12 and folate perform several important functions in the body, including keeping the nervous system healthy. A deficiency in either of these vitamins can cause a wide range of problems, including: extreme tiredness. a lack of energy.
Symptoms of vitamin B12 or folate deficiency anaemia
Anaemia is where you have fewer red blood cells than normal or you have an abnormally low amount of a substance called haemoglobin in each red blood cell. General symptoms of anaemia may include: extreme tiredness (fatigue) lack of energy (lethargy)
Depending on the cause, the symptoms of hypersomnia may include:
Here are 10 unexpected signs of a vitamin D deficiency that may surprise you.
Sleeping 12+ hours yet feeling exhausted often indicates underlying issues like sleep disorders, thyroid problems, nutrient deficiencies, or chronic conditions. Getting comprehensive blood work and addressing root causes through medical evaluation and lifestyle changes can help restore normal energy levels.
For example, vitamins B6 and B12 play a key role in energy metabolism. However, taking large doses of these vitamins can also cause fatigue and other symptoms such as headaches, diarrhea, and nausea. Other vitamins that have been linked to fatigue include vitamin C and iron.
Key points about vitamin B12 deficiency anemia
Symptoms include weak muscles, numbness, trouble walking, nausea, weight loss, irritability, fatigue, and increased heart rate.
Conditions that affect your muscles, brain or central nervous system can all cause hypersomnia. Mental health conditions like depression may also trigger it. Injuries. Head injuries or traumatic brain injuries may cause hypersomnia or increase your risk.
What Vitamins Should You Not Take At Night? It may not be ideal to take vitamin D, B complex vitamins, and multivitamins at night. Research suggests vitamin D can interfere with the effects of melatonin and interrupt sleep. B complex vitamins may cause a boost in energy and cause sleep disruptions.
Narcolepsy is a condition that makes people very sleepy during the day and can cause them to fall asleep suddenly. Some people also have other symptoms, such as muscle weakness when they feel strong emotions. The symptoms can have serious effects on daily life.
Vitamin B12
Vitamin B12 helps make your DNA, produce red blood cells and protect your nervous system. “Red blood cells transport oxygen through your body,” explained Dr. Shah. “So, when you don't have enough B12 to produce red blood cells, oxygen doesn't get transported to your cells, which leaves you feeling tired.”
Constant fatigue can sometimes indicate a wide range of underlying medical conditions — like iron deficiency, hypothyroidism, or diabetes. There are many ways you can reduce daily fatigue. Some examples include getting more sunshine and exercise, limiting caffeine, and eating balanced meals.
The koala is famous for sleeping around 20-22 hours a day, which is about 90% of the day, due to their low-energy diet of eucalyptus leaves that requires extensive digestion. Other extremely sleepy animals include the sloth (up to 20 hours) and the brown bat (around 20 hours), with some snakes like the ball python also sleeping up to 23 hours daily.
10 Tips on How to Stop Oversleeping
If you must nap, limit it to 20-30 minutes. Create a Relaxing Bedtime Routine: Develop a calming bedtime routine to signal to your body that it's time to sleep. This could include activities like reading, taking a warm bath, or practicing relaxation techniques.
Symptoms when vitamin D is low
Symptoms of vitamin D deficiency may include: Fatigue. Not sleeping well. Bone pain or achiness.
Food. Vitamin D is found naturally in a few foods, such as the flesh of fatty fish, fish liver oils, beef liver, egg yolks, and cheese. In American diets, fortified foods (e.g., milk, breakfast cereals) provide most of the vitamin D.
Taking too much vitamin D leads to calcium buildup (hypercalcemia), causing physical signs like nausea/vomiting, fatigue/weakness, frequent urination & excessive thirst, constipation, and confusion/disorientation, alongside potential bone pain or kidney stones, often from supplements, not sun exposure.
The 3-2-1 sleep rule is a simple wind-down routine: stop eating and drinking alcohol 3 hours before bed, stop working/mentally stimulating activities 2 hours before, and turn off screens (phones, TVs) 1 hour before sleep, helping you transition to rest by reducing stimulants and preparing your mind and body. It's often part of a larger 10-3-2-1-0 rule, which also adds no caffeine 10 hours prior and no hitting snooze (0) in the morning.
Oversleeping can mess with your body clock
Too little sleep can throw off your rhythm, but so can too much. “Your circadian rhythm, your body's internal clock, relies on consistency,” says Dr. Namon. “When you regularly sleep longer than your body needs, it can actually make you feel more sluggish and disoriented.”
Oversleeping can also indicate underlying illness, depression, sleep apnea, thyroid issues, and narcolepsy. It's important to find the root cause of excessive sleepiness in order to treat it. If sleep tips like the ones above don't help, your doctor can help you sort it out. Keep calm and dream on.