Can Vitamin D Deficiency Cause Persistent Itching?

Vitamin D, known as the sunshine vitamin because of its relationship to direct sunlight, is an essential, fat-soluble vitamin responsible for a variety of bodily functions. Vitamin D's most popular purpose is to allow the body to absorb bone-building calcium. It's also involved in immune-system health. As of 2011, an estimated 24 percent of Americans have inadequate levels of vitamin D, according to the "Times Union" of Albany, New York, and as a result, are at increased risk for problems that can affect skin health.

A lot of research has been done on vitamin D in recent years. The Office of Dietary Supplements reports that getting proper vitamin D through sunshine, diet or supplementation can prevent a number of serious health problems, from bone disorders to thyroid abnormalities, cancer, diabetes and heart disease. As far as itchy skin is concerned, this problem is more likely caused by taking too much vitamin D rather than a deficiency, according to the University of Maryland Medical Center. On the other hand, diseases linked to deficiency or inadequate levels of the vitamin, including type 2 diabetes, can cause itchiness.

In 2011, researchers from the University of Toronto Psoriatic Arthritis Clinic found that people with low levels of vitamin D are more likely to have psoriatic arthritis, which is a combination of psoriasis and inflammatory arthritis. Patients who live in northern climates that get less sun actually have a higher prevalence of the condition. Conditions that can cause itchy skin, such as psoriasis, may be treated or even prevented with vitamin D, according to Consumer Reports. Psoriasis is a common problem that causes cells to accumulate on the surface of the skin quickly. Characteristics of this disease are a scaly appearance and itchy, dry patches. Psoriasis is chronic, but if treated correctly, can go into remission for long periods of time.

People with low levels of vitamin D are at risk for developing type 2 diabetes, reports the University of Maryland Medical Center. Among people with diabetes, up to 33 percent have a skin disorder. In many cases, according to the American Diabetes Association, skin problems are a first sign of diabetes. The most common symptoms that affect the skin include itching and fungal and bacterial infections. While the link between diabetes and vitamin D is pretty well established, there is no evidence that taking vitamin D will prevent or help treat the condition. The University of Maryland Medical Center reports, however, that giving infants 2,000 IU of vitamin D per day in their first year can help protect against developing type 2 diabetes later in life.

Wearing sunscreen will help prevent sunburn and skin melanomas. At the same time, however, wearing an SPF 15 sunscreen can reduce your skin's ability to produce vitamin D by 99 percent, according to Michael Holick, Ph.D., director of Bone Health Care Clinic and the Heliotherapy, Light, and Skin Research Center at Boston University Medical Center. If you're vitamin D deficient, you may have been instructed to go outside in direct sunlight for about 15 minutes, three days a week. Any longer, and you're at risk for sunburn, which can cause itchiness. Holick suggests always wearing sunscreen on your face since it's only 9 percent of the body's surface and does not produce a significant amount of vitamin D. Also, avoid sun exposure during peak daylight hours, when UV rays are most intense and more likely to cause sunburn.