Vitamin D is a fat-soluble vitamin that is important for maintaining several functions in the body, including the absorption of calcium. If your vitamin D level is too low, you may not absorb as much calcium, which can lead to weaker bones and possibly eye twitches because of the role calcium plays in muscle contraction. According to the University of Maryland Medical Center, a study of childbearing women in the northern U.S. found that 54 percent of African-American women and 42 percent of white women had low levels of vitamin D. Vitamin D can be obtained by exposure to sunlight and in foods such as fortified milk. Supplements that contain vitamin D are also available; however, because vitamin D is fat soluble, excess vitamin D will not be excreted through the urine, so you can overdose if you take too much. Talk with your doctor about the proper dose of vitamin D for your individual needs.
