What’s All the Hype About Vitamin D?
Pam Koenig, FNP
Publish Date: Thu, Mar 14th, 2013
Mrs. B recently moved to Washington County with her two young children. At her neighbor's suggestion, Mrs. B and her children started taking vitamin D3 1000 IU daily. Thinking she was 'ahead of the game', Mrs. B proudly informed her healthcare provider of this during her annual physical. When she was tested and found to be vitamin D deficient Mrs. B's surprised response was, "but I drink milk and eat cheese! What's so important about vitamin D anyway?"
Vitamin D is making headlines and getting the attention it has long deserved. A 2006 survey by the Centers for Disease Control and Prevention (CDC) found a steady upward trend of vitamin D deficiency in the U.S. over the past 20 years, affecting 42% of all Americans. There are many reasons for this widespread health problem which, left undiagnosed and untreated, can have negative health effects.
However, there is disagreement about the amount of daily vitamin D needed, cutoff points for serum blood levels, indications for a supplement and the benefits of vitamin D. The resulting confusion has led to dissimilar recommendations from healthcare providers and bewildered shoppers who wonder which bottle of vitamin D to purchase from supermarkets and pharmacies.
Vitamin D is critical for normal bone growth, healthy bones and tooth attachment. Vitamin D prevents bones from becoming soft, thin, or misshapen and, together with calcium, helps prevent osteoporosis (bone loss) and bone fractures. Studies demonstrate the importance of vitamin D for healthy cell growth, neurological and muscular function, immune system and mental health and reduction of inflammation in the body. There is a growing body of research that suggests adequate vitamin D decreases risk for some types of cancer, type 2 diabetes, multiple sclerosis, cardiovascular disease, depression, and cognitive decline
When Mrs. B asked her healthcare provider how she could increase her vitamin D level "on her own," she found that there were a number of options open to her. Vitamin D is present in wild caught salmon, canned sardines, catfish, eel, mackerel, tuna, beef liver, egg yolks, Shiitake mushrooms, fortified milk, orange juice, yogurt, cheese, breakfast cereals, and infant formula. The primary source of vitamin D is sunlight. The body makes vitamin D when skin is exposed to the sun and adequate levels can be produced with 15-20 minutes of direct exposure per day. When Mrs B. heard about the need for sunlight, she said, "But I've been told to use sun-block to decrease the 'bad' effects of the sun! Is sun-block putting me and my children at risk for Vitamin D deficiency? How would I know if my children are getting enough or too much?"
Health authorities agree that the rise in vitamin D deficiency is largely because of routine use of sun-block, reduced intake of vitamin D rich foods and increased body weight in the American population. Other risk factors for vitamin D deficiency include exclusively breastfed infants, older adults, dark skin, sedentary lifestyle, gastric bypass surgery, malabsorption problems, and people living in residential institutions and northern parts of the U.S. Anticonvulsants, steroids, weight loss medications and cholesterol drugs can also increase risk for vitamin D deficiency.
Vitamin D is fat soluble. Too much can be dangerous or even toxic There is no scientific consensus regarding vitamin D levels needed for optimum health or serum levels indicating deficiency. However, a diet which includes natural and fortified sources of vitamin D along with adequate daily sun exposure will likely provide enough vitamin D to maintain adequate levels while it is very difficult to maintain adequate serum levels with dietary sources of vitamin D alone.
The IOM, AAP and CDC recommend 400 IU of vitamin D daily for infants, 600 IU for children and adults to 70 years old, and 800 IU for adults older than 70. Pregnant or lactating women need 600 IU of vitamin D daily. The National Osteoporosis Foundation recommends 800-1000 IU for all adults over 50 years old.
Recommending supplementation remains contentious, especially when those in need of it are relatively healthy. Doubt exists regarding long-term effects of attaining and maintaining high serum vitamin D by supplementation. As well, there are certain medical conditions in which vitamin D supplementation is not recommended and could be detrimental to health.
Mrs. B's self-prescribed vitamin D supplement was inadequate and her health care provider instructed her to stop taking it. A weekly mega- dose of vitamin D was prescribed for 12 weeks after which Mrs. B's serum D level was rechecked and found to be adequate. Her healthcare provider then recommended Vitamin D3 1000 IU daily and 20" of direct daily sunlight with a plan to recheck her serum D level in one year to assure maintenance of healthy levels. Like Mrs B anyone interested in taking responsibility for their health can ask their healthcare provider for information about vitamin D levels, testing and personal risk factors.