Sleeping too much or feeling excessively sleepy (hypersomnia) is most commonly linked to deficiencies in Vitamin D, Vitamin B12, and Iron. These nutrients are vital for cellular energy and regulating your sleep-wake cycle (circadian rhythm).
A disease that makes you sleep all the time is primarily categorized as hypersomnia. This is an umbrella term for conditions causing extreme, uncontrollable daytime sleepiness or abnormally long periods of sleep.
Here are 10 unexpected signs of a vitamin D deficiency that may surprise you.
Vitamin B12 Deficiency: A Rare Cause of Excessive Daytime Sleepiness | Journal of Clinical Sleep Medicine.
Early vitamin B12 deficiency signs often involve the nervous and digestive systems. Look out for "pins and needles" sensations in your hands or feet, unexplained fatigue, brain fog, and muscle weakness. A sore, red tongue (glossitis) or sudden digestive issues like nausea and loss of appetite are also common.
When your vitamin B12 is low, you most commonly crave meat, fish, and eggs. Because your body is trying to self-correct, it instinctively signals a desire for nutrient-dense animal products that naturally contain the highest amounts of B12.
Vitamin B12 deficiency fatigue feels like deep, cellular exhaustion that doesn't improve with sleep. Because your body needs B12 to create oxygen-carrying red blood cells, this type of fatigue is often accompanied by specific physical and neurological sensations.
Sleeping 12 hours a day—a condition known as hypersomnia—is typically a red flag that your body is compensating for poor sleep quality or signaling an underlying health issue. The ideal amount of sleep for adults is generally 7 to 9 hours.
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.
Taking too much vitamin D primarily triggers a dangerous buildup of calcium in your blood (hypercalcemia). The 5 most common physical warning signs include:
Vitamin D isn't actively "drained" in the sense of being burned off, but its levels rapidly drop due to poor absorption in the gut, increased bodily storage, or medications that interfere with its processing.
Eye issues: Vision loss, night blindness and other eye symptoms are possible with deficiencies of vitamins A, B1, B2, and E. Muscle control issues: Muscle weakness or coordination difficulties can happen with deficiencies of vitamins B1, B12 and E.
Drinks high in vitamin D are rarely natural; instead, they are primarily fortified milk alternatives and citrus juices, alongside specialized nutritional shakes. A standard 8-ounce serving can provide about 100100100 to 185 IU of vitamin D, helping you reach your daily recommended intake.
Health conditions can cause oversleeping
While everyone occasionally sleeps in, chronic oversleeping — needing 10, 11 or more hours regularly — can be linked to underlying health issues. “Conditions like thyroid disorders, anemia or sleep apnea can all lead to excessive fatigue and longer sleep durations,” says Dr.
Too much sleep — as well as not enough sleep — raises the risk of chronic diseases, such as coronary heart disease, diabetes, anxiety and obesity in adults age 45 and older. Sleeping too much puts you at greater risk of coronary heart disease, stroke and diabetes than sleeping too little.
Feeling exhausted and wanting to sleep all the time usually stems from poor sleep hygiene, stress, nutrient deficiencies, or underlying medical conditions like an underactive thyroid or sleep apnea. Identifying the root cause is the first step toward regaining your energy.
What are the symptoms of vitamin D deficiency?
For extreme fatigue, the most effective vitamins and minerals are Vitamin B12, Iron, Vitamin D, and Magnesium. A deficiency in these key nutrients directly impairs your body’s cellular energy production and oxygen transport.
Early vitamin B12 deficiency signs often involve the nervous and digestive systems. Look out for "pins and needles" sensations in your hands or feet, unexplained fatigue, brain fog, and muscle weakness. A sore, red tongue (glossitis) or sudden digestive issues like nausea and loss of appetite are also common.
Chronic oversleeping or an uncontrollable need for sleep (hypersomnia) can be caused by various medical, neurological, and mental health conditions. If you are experiencing excessive sleepiness, it is important to consult a healthcare provider or sleep specialist to identify the exact cause.
There are two common frameworks associated with sleep that go by the "3-3-3" rule.
In spiritual and wellness contexts, the "forbidden" or heavily discouraged sleeping position is lying flat on your stomach. This position (the prone position) is often actively avoided for physical and traditional health reasons:
Vitamin B12 deficiency progresses through four distinct phases, escalating from low blood serum levels to irreversible neurological damage. Because the body stores years of B12 in the liver, the condition develops slowly, making early biochemical or cellular detection vital for preventing serious symptoms.
The foods highest in vitamin B12 are animal products, with beef liver and clams containing the most concentrated amounts.
Brain fog is frequently caused by deficiencies in essential vitamins and minerals that support energy production and neurotransmitter synthesis. The most common nutritional culprits are Vitamin B12, Vitamin D, Iron, Magnesium, and Omega-3 fatty acids.