Getting enough, but not too much, vitamin D is needed to keep your body functioning well. Vitamin D helps with strong bones and may help prevent some cancers. Symptoms of vitamin D deficiency can include muscle weakness, pain, fatigue and depression. To get enough D, look to certain foods, supplements, and carefully planned sunlight.
Vitamin D deficiency means that you do not have enough vitamin D in your body. Vitamin D is unique because your skin actually produces it by using sunlight. Fair-skinned individuals and those who are younger convert sunshine into vitamin D far better than those who are darker-skinned and over age 50.

Vitamin D Deficiency. Symptoms, Causes and Treatment || 2020.