Vitamin D Facts
Recommended Daily Intake
Nutritionists once based recommendations for daily vitamin D intake solely on the amount needed to prevent rickets. But because scientists now recognize vitamin D’s role in so many critical physiological functions, experts now recommend 200 IU for adults under 50, 400 IU for adults ages 51 to 70, and 600 IU for adults over 70.
Infants and Children
In 2008, the American Academy of Pediatrics (AAP) revised its recommended daily intake of vitamins D for infants and children to 400 IU. Additionally, the AAP recommends vitamin D supplements for breast-fed and partially breast-fed infants as well as non-breast-fed infants and children who drink less than one liter of vitamin D-fortified milk for formula per day.
Symptoms of Deficiency
Symptoms of vitamin D deficiency include muscle pain, muscle twitching, visual problems, bone pain, anemia, diarrhea, join pain, insomnia, nervousness and a burning sensation in the mouth. If you have any of these symptoms and suspect a deficiency, consult with your physician for proper diagnosis and treatment.
Who’s at Risk?
Several population groups in the United States are at particular risk for vitamin D deficiency. These groups fall broadly into several categories, including people with limited sun exposure, the elderly, people with certain health conditions, exclusively breast-fed infants and people taking certain medications.
Those with limited sun exposure
Sunlight exposure alone provides many with sufficient quantities of vitamin D, but people with dark skin and limited exposure to the sun should be especially careful to ensure adequate vitamin D intake form diet and supplements. People who live in northern latitudes and those who routinely protect themselves from the sun with sunscreen and clothing are especially prone to vitamin D deficiency.
As we age, our ability to synthesize vitamin D from sunlight decrease, resulting in lower vitamin D levels. Additionally, the elderly are more likely to spend time indoors and out of the sun. for older adults, the benefits of supplemental vitamin D in preventing disease and prolonging life are especially important.
Those with health conditions
Several health conditions can affect the absorption and metabolism of vitamin D. people with these conditions should consult with their physician to determine appropriate supplementation strategies. These conditions include obesity, fat malabsorption syndromes (such as cystic fibrosis and cholestatic liver disease), inflammatory bowel disease and Crohn’s disease.
Exclusively breast-fed infants
Human milk contains only 25 IU of vitamin D per liter, so exclusively breast-fed infants need supplemental vitamin D to reach the recommended daily intake of 400 IU.
Those taking medications
Certain medications can interfere with vitamin D absorption. These medications include barbiturates, corticosteroids, antacids and statins (cholesterol-lowering drugs). People taking these medications should consider vitamin D supplementation to ensure sufficient intake.
An important study in 2008 reveals that inadequate vitamin intake significantly increases overall mortality. In the study, researchers at Johns Hopkins University followed a group of 13,000 initially healthy men and women for more than eight years. During this period, 1,806 people died, including 400 who were deficient in vitamin D. Led author Dr. Michal Melamed summarized the study’s results: “Those who had the lowest levels of vitamin D had a 26 percent higher risk of death from all causes compared to those with the highest vitamin D levels”.
Scientists have long recognized the importance of vitamin D in human health, but recent studies have forced the medical world to reevaluate the role vitamin D plays in preventing disease. Dr. Michael F. Holick, director of the Vitamin D, Skin and Bone Research Laboratory at Boston University Medical Center, said, “We know that being vitamin D sufficient reduces the risk of having your first heart attack by more than 50 percent, reduces the risk of having peripheral vascular disease by as much as 80 percent, and decreases the risk of prostate, colon, breast and a whole host of other cancers by as much as 50 to 70 percent”.