Vitamin Deficiency: Which vitamin deficiency Makes You Feel Sleepy?

Feeling unusually sleepy during the daytime, even after a normal night’s sleep, can be due in part to factors related to lifestyle influences. However, in most cases, vitamin deficiencies contribute to chronic fatigue and daytime sleepiness, in particular. 

Vitamin D Deficiency and Excessive Daytime Sleepiness

The National Institutes of Health (NIH) reports that vitamin D deficiency (even when you are physically active) is associated with excessive sleepiness during wake time, as well as poor sleep quality. Evidence suggests that low vitamin D may disrupt immune regulation and inflammatory pathways in the body, which affects rest and recovery of both sleep and wake. When vitamin D levels are low, it could contribute to altered drowsiness, circadian sleep-wake cycles, lack of concentration during wake time, and subsequently fatigue during daytime. Vitamin D can be obtained in 3 ways: sunlight, diet, and supplements. Addressing vitamin D deficiency can lead to much better sleep health. 

Vitamin B12 Deficiency and Fatigue

Another deficiency causing sleepiness is vitamin B-12. The B vitamin deficiencies are not as common as vitamin D deficiency, yet they can cause fatigue, excessive sleepiness, first and foremost, neurological side effects, such as lack of concentration and poor mood. The largest source of vitamin B12 is in animal protein, including meat and fish, eggs, milk, and dairy products, which explains why vegetarians and vegans can be affected by vitamin B12 deficiency unless relying on fortified foods and/or supplements.

Folic Acid Deficiency and Indirect Fatigue

Folic Acid (B9) deficiency may not cause fatigue directly, but it can cause anemia, which leads to depleted oxygen in the body. Anemia causes weakness, fatigue, and drowsiness. Most foods high in folate are leafy green vegetables, legumes, and fortified cereals. Most foods are fortified now.

Key Takeaway

• Vitamin D deficiency is the most clear reason for fatigue.
• Folic Acid deficiency can cause fatigue directly and indirectly.
• B12 deficiency can cause fatigue/drowsiness.
• Folate deficiency causes fatigue through an indirect means of drowsiness related to anemia.

In order to foster fatigue reduction, eat fortified foods, get a reasonable amount of sunlight, and get a check-up from a physician to assess the need for supplemental nutrients. 

Disclaimer- This article is for informational purposes only. Vitamin deficiencies and sleep issues may vary; always consult a qualified healthcare professional for diagnosis and treatment.