Are you lacking in the ‘sunshine’ vitamin
Dr. Nasreen Hamidani
Updated: May 27, 2012 8:02AM
Many people are surprised to learn that they are vitamin D deficient but there are clues that might have given them a sneaking suspicion. Perhaps they rarely get any sun exposure or they eat a strict vegetarian diet. Maybe they suffer from milk allergies, are diabetic or need kidney dialysis. Perhaps they have osteoporosis or have chronic back pain. These risk factors all suggest a patient population that may be at greater risk for vitamin D deficiency.
Why it’s important
Vitamin D is essential because it helps the body to use calcium from the diet and keeps bones strong. Recent studies show that it also reduces the risk of common cancers, muscle and joint pain and perhaps multiple sclerosis. A 2009 study published in the Journal of the American College of Cardiology found that low levels of vitamin D are associated with increased risk of heart attack, stroke, high blood pressure, diabetes and obesity.
Researchers estimate that nearly half of all Americans may be lacking in the “sunshine” vitamin. Most often patients have no idea of their deficiency as they have no symptoms. Some patients have bone pain and muscle weakness, symptoms that will alert their doctor to order the 25-hydroxy vitamin D blood test. Low blood levels of vitamin D have been associated with the following:
Increased risk of death from cardiovascular disease
Cognitive impairment in older adults
Severe asthma in children
Diet: Some vegetarians can become vitamin D deficient because they don’t have enough intake of the vitamin. Most natural sources of the vitamin are animal based including fish and fish oils, egg yolks, cheese and beef liver.
Sunlight exposure: People who do not get exposed to the sun including those who are homebound, live in northern climates, or who wear long robes or head coverings for religious reasons, are at higher risk of vitamin D deficiency. Regular use of sunscreen, while important, has also contributed to a greater incidence of the deficiency as it prevents the body from absorbing vitamin D directly from the sun.
Dark skin: Individuals with dark skin are at higher risk as the pigment melanin restricts the skin’s ability to make vitamin D in response to sunlight exposure.
Kidney problems: As people age, their kidneys become less efficient at converting vitamin D to its active form.
Digestive diseases: Patients with Crohn’s disease, cystic fibrosis and celiac disease sometimes are affected as their intestines have a reduced ability to absorb vitamin D from foods eaten.
Obesity: Obese patients also are at a greater risk because vitamin D is extracted from the blood by fat cells thus changing its release into the blood circulation.
Treatment involves absorbing more of the sunshine vitamin either through sun exposure, diet, or supplements. Guidelines from the Institute for Medicine suggest a recommended dietary allowance of vitamin D of 600 international units (IU) for everyone aged 1-70, and raising it to 800 IU for adults older than 70 as well as adults who are at high risk for fractures and falls, in order to optimize bone health. Some foods that are high in vitamin D include:
Cod liver oil
Orange juice, vitamin D-fortified
Milk, vitamin D-fortified
Yogurt, vitamin D-fortified
Ready-to-eat cereal, vitamin D-fortified
Women who are 60 years old and older are routinely screened for vitamin D deficiency as part of their regular physical checkups. Men may not be tested as often but can easily be deficient in the vitamin as well. Younger patients also can be at risk depending on their lifestyle (sun exposure) and other medical conditions. In all cases, greater absorption of the vitamin can be a critical step toward ensuring optimal health, particularly for strong bones and in reducing the overall risk of bone fractures.
Nasreen Hamidani, M.D., practices internal medicine in Riverside and is on staff at Adventist Hinsdale and La Grange Memorial hospitals.