Although some changes in vision may be a natural part of aging, blurred vision may be a sign of an underlying eye disease. One cause of deteriorating vision is a condition called macular degeneration. Vitamin D deficiency may increase the risk of macular degeneration, but you should talk to a doctor before taking any supplement.
Vitamin D is present in a few foods such as fish, eggs and liver; this vitamin is also added to many dairy products. Your body can also make vitamin D when your skin is exposed to sunlight. One of the main roles of vitamin D, the Office of Dietary Supplements explains, is to help your body absorb calcium. Vitamin D also regulates cell growth, inflammation and neuromuscular function.
Causes of Blurred Vision
Blurred vision, whether in one eye or both, is a symptom of many different eye problems. Sometimes, EyeHealthWeb notes, it merely signifies the need for glasses or a new prescription lens. On the other hand, more serious conditions, such as macular degeneration, can also cause blurred vision. If you develop blurred vision, undergo a thorough examination by an optometrist or ophthalmologist.
Vitamin D and Macular Degeneration
Although the role of vitamin D in macular degeneration is still under investigation, some research suggests that adequate levels of vitamin D may be important for preventing this disease. A study published in April 2011 in "JAMA Ophthalmology" found that increased vitamin D intake reduced the risk of macular degeneration in women under 75. Another study, reported in 2012 in the "Neurobiology of Aging," suggested that vitamin D could rejuvenate eyes by reducing inflammation and improving vision.
Vitamin D Supplements
Although vitamin D deficiency can cause health problems, too much vitamin D can be dangerous. According to the Office of Dietary Supplements, consuming more than 400 international units, or IU, of vitamin D each day along with calcium supplements can increase the risk of kidney stones. Higher doses of 10,000 to 40,000 IU can lead to calcium accumulating in the heart, kidneys and blood vessels, which can cause serious health problems.