Vitamin D is included in many brands of milk, but a National Osteoporosis Foundation study found that only 40 percent of cartons tested contained the amount of vitamin D listed on the label. The other 60 percent had less than advertised.
There are two kinds of Vitamin D: D2 and D3. D2 is derived from plant sources and is cheaper, but it does not stay in the body as long as D3, which is derived from animal sources.
Genetics can play a role in determining your ability to process V…
WATERLOO - Dr. Jay Ginther had been treating patients for vitamin D deficiencies for several months before he realized that he, too, probably needed more of the nutrient.
“Vitamin D comes from the sunshine, but unfortunately, if you don’t live in the tropics you can’t get vitamin D all year round,” said Ginther, director of the Cedar Valley Bone Health Institute in Waterloo. “Right now in (early springtime in) Iowa, about 80 percent of us are deficient.”
The vitamin, a pre-hormone, has recently received increased attention from the medical community. About 75 percent of U.S. adults and teens do not get enough of the substance, according to a 2009 study in the Archives of Internal Medicine. Without adequate levels of the vitamin, the human body cannot properly absorb calcium, a key component in bone health. Deficiencies in the nutrient can also negatively affect muscle strength and balance, as well as cause fibromyalgia-like symptoms and nerve damage.
Yet vitamin D screening is not part of a routine physical. Dr. Ara Jenevizian, a family practice physician at Covenant Clinic, said those concerned about their levels should ask their health care provider for the blood test.
Some researchers believe that 15 to 30 minutes of exposure to sunlight two to three times a week is enough to obtain adequate vitamin D, Jenevizian said. That standard, and whether the recommendation could lead to an increased risk in skin cancer, will be reviewed this fall by the National Institutes for Health.
“Everybody is waiting at this time for these studies that are underway to finish and come to a final conclusion,” said Jenevizian. “There are major questions about Vitamin D because so many studies have said it is much more important than we had thought in the past.”
In recent years, deficiencies in the vitamin have been linked to increased risk of autoimmune diseases, multiple sclerosis, asthma attacks, Alzheimer’s disease, seasonal affective disorder and several types of cancer.
“Usually the ultimate effect of vitamin D (deficiency) expresses itself, unfortunately, in serious conditions,” Jenevizian said.
For that reason, Ginther treats his vitamin D-deficient patients with high-dose supplements. In the northern climates it’s nearly impossible to get enough of substance - available only during the spring and summer - from sunlight, he said. And although oily fish like sardines and salmon contain Vitamin D, few people are able to acquire appropriate amounts of vitamin D from diet alone.
Adults with sufficient amounts of vitamin D in their body should take 2,000 units of the substance daily. For those with a deficit, Ginther recommends 50,000 units three times a week until the body’s stores are replenished.
Ginther started treating patients for vitamin D deficiencies, which can cause osteoporosis, about five years ago. In 2007 he tested the levels of every person he admitted to the hospital for fractures. It was May before he found a patient with a normal Vitamin D reading.
“In the last couple years we’ve started realizing just how important vitamin D is to our health,” Ginther said. “People are beginning to pay attention to it.”