Over the past year or so, I have noticed a remarkable increase in laboratory-documented vitamin D deficiency, particularly in middle-aged women. As you all know, the human body cannot make Vitamin D -- a necessary pre-requisite of healthy bone and muscle functioning. Vitamin D can only be absorbed from certain foodstuffs and sunlight.
Cow's milk comes to possess Vitamin D only through the process of "fortification" whereby your friendly local dairy pours in the supplement. Otherwise, such unadulterated dairy products as cheese and yogurt -- although high in calcium -- maintain no significant levels of Vitamin D.
Thus, many women attempting to prevent osteoporosis may erroneously believe that a high-calcium diet comprised of Tums, cheese, and yogurt -- and devoid of fortified milk -- may be adequate. They are obviously wrong. Indeed, all the Boniva and Reclast in the world won't help build healthy bone on a D-deficient matrix -- kind of like attempting to put fresh plaster on a crumbling concrete surface.
Women aren't the only ones at risk for this disorder. Men on corticosteroids, proton pump inhibitors (anti-ulcer drugs), or anti-seizure compounds show similar pre-disposition. Moreover, the dermatogists have done a fantastic job of mandating sun avoidance and various cosmetics, thus impeding a solar source of Vitamin D. Hi-SPF Coppertone may be great for that creamy complexion, but is actually preventing sunlight manufacture of an important nutrient.
Back in the day we didn't see so much of this deficiency as Granny would typically walk to the bus stop; hang laundry in the back yard; and take her afternoon iced tea on the front porch. Nowadays, we leave our air-conditioned garages in sun-tinted vehicles on our way to the undercovered parking at our local climate controlled mall or office building. Thus, modern American humans have less and less exposure to sunlight.
Typical, clinical symptoms of Vitamin D deficiency include muscle aches, bone fractures, headache, and difficulty concentrating. It doesn't take a full blown case of Rickets to make the diagnosis. Only a doctor's suspicion and the appropriate blood test.
Although, not a proponent of mega-vitamin supplements, I do recommend a simple test for all middle aged people -- particularly those city folk who may be at risk.