Women’s Flat Track Roller Derby Magazine
John Rudoff, M.D., FAC aka Johnny the Knife
Fact of life: rollergirls fall down. A lot. Usually they go splat, but occasionally they go crunch. Your bones take a beating, and so we’ll start talking about vitamin D in the usual way – concerning healthy and strong bones. But we won’t end there. Vitamin D is a lot more interesting than just bones.
Vitamin D (we’ll now just call it D) allows the gut to absorb calcium and phosphorus, and without adequate D, bone is neither dense nor strong. Various conditions can be the result: osteomalacia, osteopenia or osteoporosis. If your circulating D levels are inadequate, you cannot absorb more than 10-15% of the calcium you consume. Without calcium, you cannot make strong bone. Females make most of their bone and bone strength between about ages 16 and 35, and they lose bone strength progressively through menopause and into old age. If you don’t make lots of good bone now, you can’t play catch-up later in life. If you go into menopause with light, poorly-calcified bones, you may be destined for an old age of hip and vertebral fractures, a “dowager’s hump” (that stooped, bent-at-the-shoulder shape of older women with terribly painful compression fractures of the spine), and easily fractured wrists and legs.
Historically, the minimum requirement of D for adults was 400 Units (400 IU). This is far too low. It was calculated back in the 1920s to show how much D was the minimum needed to prevent rickets in children in working-class, cloudy England. This requirement has not really been definitively updated. Women athletes need far more than this “minimum.” The good news is that you can get all you need for a dollar a month.
Vitamin D is produced in a complex series of steps, starting with the effect of sunlight on skin and then involving the actions of the liver and the kidney. This may suggest that diet and sunlight alone provide enough D. They don’t. This is why supplementation is needed – foods are a poor source of D, and, unlike our hunter-gatherer ancestors, we don’t spend enough time half-naked, outside, in the sun, making D (and dying of disease or trauma at 35.) This is a peculiarity of D – calling it a vitamin suggests that it is easily obtained through proper diet or with sunshine alone. It isn’t. 50% of Hawaiian adults receiving three hours of sun per day were D deficient. 40% of south Floridians and 25% of Arizonans were deficient. Dietary sources of D, such as cod liver oil (when was the last time you took that?!), oily fish, fortified milk or orange juice, will not reliably give you anywhere near enough D.
Generally (and there is some disagreement among experts), a D level (this is called 25(OH)D) of less than 20 ng/ml is labeled deficient; about 21-30 is insufficienct, and more than 30 is adequate. Many experts are suggesting a target level in the range of about 35-40, however. This is easily attained.
What types of people are at risk for deficiency? People who live in northern latitudes, like Portland’s Rose City Rollers, who rarely see sunshine from October through April. People who work and/or exercise indoors (flat track derby isn’t an outdoor sport). Black people – the melanin in their skin prevents sun absorption and creation of D. Obese or even overweight people tend to “hide” D in fat, so they need more D to get adequate amounts circulating. Fair-skinned people who regularly use sunblock: even SPF 15 will reduce D production by more than 90%. Much less commonly, people with kidney disease or fat malabsorption syndromes need massive D supplementation; but this is a special issue.
You see, the common factor is lack of sunlight. This is why supplementation of D is important: using sunlight on skin to produce D increases the total lifetime risk of skin cancers (including the lethal melanoma) in long-lived modern people. This is why the American Academy of Dermatology wisely says “…(D) should not be obtained from unprotected exposure to ultraviolet (UV) radiation.”
But that’s all the dull stuff. Now it gets cool. Remember… it’s not just for bones anymore. We’ll talk about cancer, pain, brainpower, arthritis, and (my favorite) heart disease.
Most cells in the body have vitamin D receptors – meaning that D can affect the actions and consequences of most cells in the body. Vitamin D reduces cell proliferation (uncontrolled growth), reduces angioneogenesis (which is the formation of new microscopic blood vessels needed for tumors to develop and to metastasize), and also controls the appropriate timing of cell death. Recent interesting studies (in peer-reviewed mainstream conventional medical journals) suggest that D supplementation, or adequate circulating levels of D, are associated with a reduction in cancer incidence, particularly breast, colon, bladder, mouth, and leukemia. Further, because of the mechanisms of action of D, it appears that people with some cancers (especially colon) who have adequate D are less likely to die of that cancer than are people who are D-deficient.
Chronic pain may be related to D deficiency. (Yes, it may also have something to do with falls, collisions, and workouts.) Severe deficiency is associated with chronic muscle and bone pain, low back pain and possibly with nerve pain (neuropathy) of the sort seen in diabetes. This type of pain may be severe and life-altering, and it is felt in the hands and especially the feet and legs.
D affects heart muscle and arteries, overall heart function, and survival, too. This means that a population which is D-deficient has a total mortality much greater than an otherwise similar population that has normal levels of D – and most of that excess death is due to heart disease. Low D levels are associated with double the risk of heart attack and nearly double the risk of general heart-related death. This seems to be indirect, because D deficiency is associated with all the direct heart-disease risk factors, such as high blood pressure, abnormal cholesterol, both diabetes and excess insulin, and heart failure.
So if D deficiency is related to all this misery, and it’s easy to fix, why are so many people D-deficient? Until recently, the metabolic effects of vitamin D were not appreciated, and its effects were thought to be limited to bone production. That’s why I wrote this article.
One question comes to mind: do you need to be tested? It is cheap (about $40-45) and commonly available. Many experts, especially bone gurus, would say that if you don’t have risk factors for severe deficiency, or the inability to absorb D supplementation, they would not test you. In general, I would recommend against it, particularly if finances are important. The likelihood of “toxicity”(too much D) is almost unheard of.
Instead; go to any Costco, chain supermarket, or discount store and buy a bottle of 2,000 units of Vitamin D3. (This is vitamin D3, also called Cholecalciferol. Don’t buy Vitamin D2, called Ergocalciferol.) At Costco, nearly 2 years’ supply, 600 tablets, costs about $14. Take one a day faithfully. There are no side effects. After 6 months, if your finances are OK, get a vitamin D test. If the level is greater than 30-35 or so, keep taking the vitamin D forever. If it isn’t, see a doc (a medical doctor, namely an M.D. or D.O.) who knows something about endocrinology. The combination calcium-vitamin D tablets (like Os-Cal or Viactiv) do not provide enough D – usually only 400 units. Take a couple of daily TUMS instead. If you already have bone problems – such as unexplained fractures, X-rays showing osteopenia and so on – then testing your baseline level of D might be reasonable.
Major warning!! You do not need any sort of expensive or special supplements, especially if sold by naturopaths or Internet charlatans. Avoid these quacks like the plague – they will take your money, frighten you, and they will not provide you with any special, secret formulation of Vitamin D that your body utilizes better than the product you get from Costco or Target. (There is a similar scam with “coral calcium” that has gone on for years. You want more calcium? Take TUMS along with your D.)
Johnny the Knife is a cardiologist, derby groupie, photographer and hanger-on with the Rose City Rollers of Portland, Oregon.