Vitamin D

Vitamin D Debacle
We have heard a lot of questions this week concerning the recently released Institute of Medicine’s (IOM) ‘new and improved’ recommendations for vitamin D and calcium intake.  While the Institute’s recommendations about calcium seem to be agreed upon by most, the recommendations released for vitamin D have caused quite a stir in groups of health care providers across the country.
To begin with, let’s review what Vitamin D does for us.  Whether through dietary intake or good old sunshine, once active Vitamin D has gotten into our systems, it plays a very valuable role.  Our immune system is greatly influenced by D, to the tune of increased and enhanced immune cell function. Vitamin D also assists with the very intricate regulation of calcium in the body— so without it, calcium cannot be absorbed nor integrated into our bones, therefore decreasing the integrity of our skeletal system (which, as it turns out, is actually pretty important to us).   The uncontrolled dividing of cells (AKA: rapid proliferation) and lack of cellular differentiation, which leads to the formation of cancers in the body, can be halted by the active form of Vitamin D.  It also plays a role in blood pressure regulation and insulin secretion as well as a host of other functions.  (To find out more, read a little here: http://lpi.oregonstate.edu/infocenter/vitamins/vitaminD/)
The actual IOM report is quite a tome, weighing in at total of 990 pages long.  (If you have a free weekend, take a gander for yourself: http://books.nap.edu/openbook.php?record_id=13050)  To be honest, I did NOT comb through all 1000 of the research articles that the IOM used in its decision making process.  Here are the basics: They have raised the suggested daily intake from 400 to 600 IUs of Vitamin D.
The other half of the research is focused on the suggested calcium supplement intakes (Not taking into account food-based calcium, how you prepare that food and what types of foods….).  At the end of it all, the researchers are saying that the recommended intake is 600 IUs (800 in the elderly, 400 in wee ones), but the upper tolerable limit, where “the risk of harm increases,” is 4,000 IU per day.  I feel that the intake recommendations are overly conservative, and quite limiting in light of the potential benefits that Vitamin D can offer.
The IOM is also recommending that threshold for Vitamin D testing be at the 20 ng/ml level. We generally like to see the levels around 80 ng/mls, but most people in the Northwest clock in around 20-30 on an initial screen.  Many of the studies quoted and used to formulate the new recommendations are based in toxicity studies.   It looks like the toxicity studies that they used for adults all included doses of Vit D of 100,000 to 150,000 IUs of Vitamin D a day for anywhere from 3-4 weeks to several years years….increasing the blood levels up anywhere from 150 to the 1000’s.  This is way too high! Other studies used are based off of cases of accidental over-fortification, which is very different than the supplemental Vitamin D that our patients have come to know and love.   Overall, not the most convincing body of evidence to base new lab levels on.
The best rebuttal to the statements made in the research came from the Vitamin D Council.  Here is that link:
http://www.vitamindcouncil.org/vdc-statement-fnb-vitamin-d-report.shtml
It is fairly humorous and mildly thick with disgust for claimed data mis-interpretation and deletion that is in the IOM statement.  Here are the salient response jabs:
–“After 13 year of silence, the quasi governmental agency, the Institute of Medicine’s (IOM) Food and Nutrition Board (FNB), today recommended that a three-pound premature infant take virtually the same amount of Vitamin D as a 300 pound pregnant woman.”
–“As a single, 30 minute dose of summer sunshine gives adults more than 10,000 IU (250 micrograms), the FNB is apparently also warning that natural Vitamin D input — as occurred from the sun before the widespread use of sunscreen — is dangerous. That is, the FNB is implying that God does not know what she is doing.”
–“Today, the FNB has failed millions of pregnant women whose as yet unborn babies will pay the price. Let us hope the FNB will comply with the spirit of “transparency” by quickly responding to our Freedom of Information requests.”
Another great article was on the Huffington Post by Dr. David Katz, whose work I generally enjoy and his articles seem to have a good enough natural-based-bent to them.
http://www.huffingtonpost.com/david-katz-md/vitamind–andcalcium-shouldwe–becautious_b_789842.html
His summary is as follows:
“Calcium and vitamin D are important nutrients. As with all nutrients, enough is good — too little or too much is bad. The IOM invokes the precautionary principle to offer recommendations that are reasonable, and willfully conservative. But a relative absence of evidence means that guidance is as much about judgment as science.”
I think at the end of it all, what I am falling back on is that checking patients’ blood levels, like any therapy we initiate, is key.  Yes, 5,000 to 10,000 IUs of Vitamin D for YEARS and YEARS might be too much (again, not enough data to support or negate).
But keeping people on 1000 to 4000 daily as a maintenance dose (and, of course, using higher doses when clinically needed) while keeping blood levels in check, is JUST FINE.
Especially in Portland, where our 2 months of partial sun in 2010 has us all a little cranky and seasonally affected.

We often hear questions concerning the ‘new and improved’ recommendations for Vitamin D and Calcium intake (from the Institute of Medicine) .  While the Institute’s recommendations about Calcium seem to be agreed upon by most, the recommendations released for Vitamin D have caused quite a stir in groups of health care providers across the country.

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The actual IOM report is quite dense and a total of 990 pages long.  (If you have a free weekend, take a gander for yourself.)  To be honest, I did NOT comb through all 100 of the research articles that the IOM used to make its recommendations.  But here are the basic recommendations:

Raise the suggested daily intake from 400 to 600 IUs of Vitamin D. The other half of the research is focused on the suggested Calcium supplement intakes (Not taking into account food-based Calcium, how you prepare that food and what types of foods…).  At the end of it all, the researchers are saying that the recommended intake is 600 IUs (800 in the elderly, 400 in wee ones), but the upper tolerable limit, where “the risk of harm increases,” is 4,000 IU per day.  I feel that the intake recommendations are overly conservative, and quite limiting in light of the potential benefits that Vitamin D can offer.

The IOM is also recommending that threshold for Vitamin D testing be at the 20 ng/ml level. We generally like to see the levels around 80 ng/mls, but most people in the Northwest clock in around 20-30 on an initial screen.

Many of the studies quoted and used to formulate the new recommendations are based in toxicity studies.   It looks like the toxicity studies that they used for adults all included doses of Vit D of 100,000 to 150,000 IUs of Vitamin D a day for anywhere from 3-4 weeks to several years… increasing the blood levels to anywhere from 150 to the 1000’s.  This is way too high and clearly excessive supplementation!

Other studies used are based off of cases of accidental over-fortification, which is very different than the supplemental Vitamin D that our patients have come to know and love.

Another interesting article on the topic came from a Huffington Post contributor, from Dr. David Katz, whose work I generally enjoy and whose articles seem to have a natural-based-bent to them.

“Calcium and vitamin D are important nutrients. As with all nutrients, enough is good — too little or too much is bad. The IOM invokes the precautionary principle to offer recommendations that are reasonable, and willfully conservative. But a relative absence of evidence means that guidance is as much about judgment as science.”

I think at the end of it all, what I am falling back on is that checking patients’ blood levels, like any therapy we initiate, is key.

Clearly, 5,000 to 10,000 IUs of Vitamin D for extended periods of time (YEARS and YEARS) or in the presence of naturally high blood levels is likely too much (although, the data to support or negate has yet to be generated sufficiently).

However, across the upper latitudes (Oregon, Washington, Canada, Norway, Sweden, etc..) providers have found 1000 to 4000 IU daily as a maintenance dose (and, of course, using higher/lower doses when clinically indicated) does not result in unusually elevated blood levels.

The key, then is making sure that you are supplementing under the care of a provider who evaluates your Vitamin D blood levels as indicated and supports you in making informed decisions to optimize your health.

Getting your Vitamin D levels checked should be part of every person’s winter health regimen. If you haven’t been tested this year, call the clinic today at (503) 287-4970, or email info@naturecuresclinic.com for an appointment.

Image courtesy: SeanMcGrath