(NaturalNews) Growing awareness about the prevalence and risks of vitamin D deficiency is leading more and more doctors to test their patients' blood levels of the vitamin.
"Upwards of 70 percent of American adults are vitamin D deficient or insufficient," said cardiologist James O'Keefe of St. Luke's Mid-America Heart Institute. "In the last year, awareness of vitamin D deficiency has really exploded."
Vitamin D is more properly classified as a hormone, and it helps regulate gene function in various parts of the body. It is naturally synthesized in the skin upon exposure to ultraviolet radiation from sunlight, but sedentism and growing use of sunblock have worsened deficiency rates in recent decades.
According to O'Keefe, vitamin D testing has become the most popular "a la carte" blood test ordered by doctors in the past year. The test costs about $100, and is covered by some insurance providers.
Vitamin D is known to play a role in bone health and immune function, but many doctors are now fingering deficiency for a number of more general complaints. Carla Aamodt, another doctor at St. Luke's, notes that when she orders supplementation for patients with vitamin D levels below 10 nanograms per milliliter, the patients feel better overall, have more energy with less muscle aches and pains."
The jury is still out on optimal vitamin D levels, but researchers agree that they fall somewhere between 30 and 40 nanograms per milliliter.
Billie Howard Barnes of Kansas City suffered from chronic pain until her doctor ordered a vitamin D test and discovered that her blood levels were a paltry 5 nanograms per milliliter.
"I'm 43, and getting up in the morning, my feet would hit the floor and every joint in my body was sore," Barnes said. "I didn't realize how bad it had gotten. It just kind of crept up on me."
After taking a high-dose supplement for a few weeks, Barnes began to recover.
"It wasn't an instant thing, but I just feel much better," she said. "I'm not as stiff. Colleagues say there's more pep in my step."