2. You are always tired and never feel well-rested
It doesn’t matter how much sleep you are getting, you always feel like you are tired. If that’s the case, it could very well be that you are suffering a vitamin D deficiency. Several studies have found that very low levels of vitamin D can cause severe fatigue, which in turn, can have negative effects on your overall health and your quality of life. If you are deficient in vitamin D, it doesn’t matter how much sleep you get, and how good that sleep is, you aren’t going to feel well-rested. Taking a vitamin D supplement, getting more sunshine or eating foods that are high in vitamin D can help to alleviate the problem.