Not feeling quite like yourself? A lack of Vitamin D could be to blame. This important fat-soluble vitamin plays a critical role in helping the body absorb calcium, maintain strong, bones, and elevate mood, and energy levels.
But certain diseases, increased age, darker skin, and lack of sun exposure can all diminish important Vitamin D stores. Here are just a few of the symptoms that could mean you’re super low on Vitamin D:

Fatigue. One of the most common symptoms of low Vitamin D is fatigue. A 2014 study published in the North American Journal of Medical Sciences noted that a “very high prevalence” of patients who were low on Vitamin D complained of fatigue. Fortunately, there was a “significant reduction” in fatigue once Vitamin D levels were restored.

Bone and Joint Pain. According to the Cleveland Clinic, another common symptom caused by a lack of Vitamin D is bone and joint pain, including chronic low-back pain. A severe Vitamin D deficiency can also cause a softening of the bones known as rickets.

Depression and Mood Swings. A recent review of 61 scientific studies has documented a relationship between depression and abnormally low levels of Vitamin D. There is also a correlation between Vitamin D deficiency and being at greater risk of developing Alzheimer’s disease and dementia.

Hair Loss. Several scientific papers have revealed that Vitamin D insufficiency may cause hair to fall out. A patchy form of hair loss known as alopecia areata that occurs when the body’s immune system attacks the hair follicles has also been tied to low levels of Vitamin D.

Cardiovascular Disease. Decreased Vitamin D may play a role in increased cardiovascular diseases such as hypertension and peripheral artery disease (PAD). It’s believed that Vitamin D’s anti-inflammatory properties may help guard against these serious conditions.

Luckily, Vitamin D can be found in common foods like salmon, tuna, egg yolks, and mushrooms and is also available in fortified bread, cereals, and dairy products. Vitamin D can also be produced by the human body when it’s exposed to sunlight.