Jan Wagner refused to believe her fatigue, hip pain, inability to concentrate and feeling "like a vampire had sucked the life out" of her were because of her increased workouts or because of her age.
It turned out the 50-something paralegal was right. Her health was being clouded by a lack of vitamin D, commonly called the sunshine vitamin because the body naturally produces it by spending as little as 15 minutes in the sun each day.
Wagner is one of thousands of Wichitans who've been diagnosed with the deficiency in the past 18 months. And her cure has been as simple as picking up a bottle of supplements at a local discount store.
In just the past two months, a Wichita lab has done more than 1,700 vitamin D tests for area doctors, with more than 47 percent of those tests showing low levels, according to Bill Combs, manager of Affiliated Medical Services Laboratory.
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It's become such a prevalent cause of so many of his patients' ailments that Aaron Fields, a local osteopath, now makes it routine to order the test.
"It's becoming part of my screening tests, just like testing cholesterol levels," said Fields, with Via Christi Medical Associates in Goddard. "I'm into prevention, and vitamin D is a big piece of the prevention puzzle."
Hot topic in medicine
Vitamin D deficiency has become a hot topic among physicians and a widespread health concern for people of all ages. It's long been understood that vitamin D helps with the absorption of calcium, necessary for good bone health. Now the deficiency is being linked to health conditions ranging from depression to heart disease, from autoimmune diseases to cancer.
"I graduated from residency in 2006 and I don't remember anybody once every talking about the deficiency back then," Fields said.
Doctors are reading about vitamin D studies in respected medical publications, and many are starting to order testing for the vitamin deficiency more regularly, as Fields does.
"I think the studies have really lit a fire under the medical community since the deficiency is linked to so many diseases," said Ed Harned, president of AMS Labs, an affiliate of Via Christi Health. The tests have also become more affordable, leading to more doctors being willing to order the test.
At AMS Labs, located at 2916 E. Central, or one of its four service centers, consumers can have the test done directly for $25. Lab officials encourage consulting with a health care professional to interpret the tests, however.
Eighteen months ago, the lab was sending about 800 tests a month to the Mayo Clinic. Now AMS, which has been conducting the tests in-house since March 15, runs close to 1,000 a month.
The volume has gone up so significantly that the lab decided to invest in equipment and training to run the same standard of testing used at Mayo Clinic. It's the only lab in Kansas, outside of the Kansas City area, to use liquid chromatography/double mass spectrometry, the most sophisticated way to test for the deficiency.
On a recent Monday morning, medical technologist Heather Cox completed 66 tests, a typical volume coming off a weekend. Testing for vitamin D levels has become her full-time job.
What vitamin D is
Vitamin D isn't really a vitamin, it's more of a hormone, Combs, the AMS Lab manager, said.
It's the building block of calcitriol, a powerful steroid hormone in the body. While it works with other nutrients and hormones to support healthy bones, researchers are finding it does a whole lot more.
"Muscles need it to move, nerves need it to carry messages between the brain and every body part, and the immune system needs vitamin D to fight off invading bacteria and viruses," according to a National Institutes of Health fact sheet.
It's a fat-soluble vitamin, meaning it needs fat to be absorbed. However, being obese is one of the risk factors for a vitamin D deficiency, research shows.
When one's skin is directly exposed to the sun, the body can produce it. However, sunscreen — the use of which has become an important practice for reducing the risk of skin cancer — acts as a barrier.
Vitamin D has two forms, D2 and D3. The D3 form is considered better because it keeps levels of vitamin D in the bloodstream raised for a longer time, according to the NIH.
The levels are generally measured as nanograms per milliliter (ng/mL), with the 30-70 ng/mL being the recommended range.
"Mine was cruising at 10," recalled Wagner.
Fields had one patient register at 3.
"If you are alive and spend most of your time indoors ... chances are you're probably deficient," Fields said.
Raise your levels
So how does one lift the cloud that vitamin D deficiency seems to produce? More than a half-century ago, when rickets, a known result of vitamin D deficiency, was more common, doctors recommended taking cod liver oil. The push to prevent rickets is what led to some foods and beverages, such as cereal and milk, to be fortified with vitamin D.
But those fortified foods don't contain enough to raise anyone's level, experts say.
"You'll never get there by relying on fortified-D foods," Fields said. Only a few foods, such as fatty fish, naturally have vitamin D.
The best medicine is to get about 2,000 international units, or IU, a day, Fields said. Supplements are readily available at grocery, discount or health food stores. If someone is severely deficient, Fields may prescribe a once-weekly dose of 50,000 IU for a short period.
A person should be retested for vitamin D levels within two to three months after treatment with supplements, doctors say.
Wagner, who will be retested in June, said she's already feeling the benefits of being on supplements since March. She has more energy and her personal trainer is working her harder than ever, she said, and she's not feeling any of the bone pain or constant fatigue that had set in last fall.
Who's more at risk
Vitamin D deficiency is becoming a fairly common condition for many Americans. However, there are certain groups of people who may be more at risk for the deficiency, according to the National Institutes of Health.
* People living in the northern half of the U.S., above a line between Boston and the northern border of California. The energy of the sun isn't enough for the skin to make vitamin D during the coldest months there.
* Breast-fed infants. Human milk is a poor source, so the American Academy of Pediatrics advises that breast-fed infants, even if they are only partially breast-fed, be given a supplement.
* Older adults. As people age, their skin can't produce vitamin D as efficiently and their kidneys can't convert it as well, either.
* People with dark skin. A higher level of the pigment melanin means less ability to produce vitamin D from the sun.
* People with disorders such as Crohn's disease or celiac disease, because they can't handle fat properly. Vitamin D needs fat to be absorbed.
* Obese people. The body fat in people with a body mass index of 30 or higher binds to some vitamin D, preventing it from getting into the bloodstream.