Minnesota Academy of Family Physicians

To Vitamin "D" or Not to "D"? A Family Physician Tackles the Question
-Patient Education from the Minnesota Academy of Family Physicians-

June 15, 2011

If you’ve watched any health segments on TV or read the “For Your Health” sections of popular magazines and newspapers lately, you’ve probably come across an article or two about using Vitamin D.

“Many of the reports are glowing and make it sound like it’s the next thing that should be added to the public water supply,” said Dr. Glenn Nemec, a family physician who practices at Monticello Clinic in Monticello, MN. “Others have been more cautionary, and even alarmist, over the amount of sun exposure needed to reap all of Vitamin D’s supposed benefits.” As is true with many public media presentations on NEW medical information, Dr. Nemec says the benefits have been a bit overstated, and the harms either over-rated or completely un-rated.

So what should the average health-conscious consumer conclude from the often conflicting information? For those who want to cut to the chase, Dr. Nemec encourages them to make an appointment with their family physician to talk about how their personal health status (diseases, risks, medical history, personal health habits, etc.) impacts the likelihood of Vitamin D problems being a concern. “Family physicians are trained to sift through the data and apply it correctly to YOUR health situation. There is not a “one size fits all” solution for the Vitamin D conundrum,” said Dr. Nemec.

For those who like to dig a little deeper, the following is a basic primer on the main points in the Vitamin D story.

What is Known About Vitamin D

If you are terribly deficient, you get rickets.
If you have osteopenia or osteoporosis, and you are even a little deficient, you have a much higher risk of ending up with broken bones due to weakened bone
structure. If you get your Vitamin D levels up, you decrease your risk of those bone breaks.
People with fibromyalgia and seasonal affective disorder who have low levels of Vitamin D, show clinical improvement (i.e. they feel better) if they get their Vitamin D levels up.
Vitamin D is manufactured by the skin when the skin is exposed to ultaviolet (UV) sunlight. There is very little of it in any of the foods Americans commonly eat, except for milk, to which it is added. From late September to early May, almost all of the ultraviolet sunlight is reflected into space by the upper layers of the atmosphere unless you live south of Evansville, Indiana (southernmost town in Indiana). If you wear sunblock you prevent the skin from producing Vitamin D, if you don't wear sunblock, your skin ages faster and you probably get more skin cancer.

Dr. Nemec says there is a lot of research going on in a lot of other areas, but no hard facts yet. A host of seemingly unrelated medical conditions have either higher frequencies in people with lower levels of Vitamin D, or lower frequencies in people with higher levels of Vitamin D. These are called “associations”. Associations DO NOT mean Vitamin D either causes or prevents the particular disease. All it means is that it has been noticed that the two things often go together.

“One should note that in humans, large shoe size and high IQ are “associated”. Intelligence does not cause big feet, and big feet do not make you smarter,” said Dr. Nemec. “The lesson is, don’t jump to conclusions, and don’t mistake associations for causation.”

Second, a perceptive person will begin to see how an individual person’s recommendations about what to do about Vitamin D change, based on a lot of individual factors. For example, a person who lives in Minnesota, drinks three glasses of milk every day, gets regular weight bearing exercise (strengthens bones), is out in the sun without sunblock almost daily during the warmer months, is African-American (low risk for skin cancer), and feels fine (no depression or fibromyalgia), probably doesn’t need to know what their Vitamin D level is because they’re at such low risk for any of the proven Vitamin D diseases, and also at low risk for the skin diseases caused by UV exposure. Now take another Minnesotan who is a fair skinned, indoor type, couch potato, milk intolerant, a compulsive sunblock user, and has fibromyalgia. They probably don’t need a Vitamin D level done either, it’s almost certainly low, and they should probably be taking a fairly high dose of Vitamin D year round. (Not to mention getting off the couch, exercising, and taking calcium.) Those are the two extremes, which are fairly easy to assess. But if just one or two of the variables are changed, each combination can result in a different overall recommendation. And this doesn’t even address how likely it is that a person will follow all those other recommendations.

This is why patients need to talk with their family doctor about Vitamin D. Like many medical decisions, something that the lay press presents in highly simplified form, turns out to be much more complex when individual circumstances are applied to the information. Media tends to sell to the masses, while information you get from your family doctor will be YOUR information.