January 14, 2016

Director's Letter 
Carole Baggerly 
Director, GrassrootsHealth 

A paper was recently published that launched an attack on vitamin D. The paper, by lead researcher Heike A. Bischoff-Ferrari, MD, Dr PH, studied whether vitamin D would prevent functional decline in 200 home-dwelling men and women in Switzerland. The researchers found that the groups assigned to the two higher monthly doses actually increased their likelihood of falls compared to the control group.

Dr. Bischoff-Ferrari presented some of the findings in this paper at the Vitamin D Workshop last April. Many of us in the vitamin D community knew these findings would be coming and really understood them. The conclusions that high monthly doses of vitamin D, or vitamin D plus calcifediol, may not be beneficial for seniors are reasonable given what we now know about bolus dosing (infrequent, large doses). In fact, high monthly doses are likely not beneficial for most people, regardless of age. Since this study was conducted, we have new information to suggest that monthly dosing does not work for non-skeletal effects of vitamin D. According to Dr. Reinhold Vieth, such doses result in a "false season" effect in the person, giving them big highs, and big lows -- that are not healthy. We do not find anything from this paper to make us change our recommendation that achieving a serum level of 40-60 ng/ml, through daily inputs of sun, supplements, and/or diet, is beneficial to overall health.

Despite our understanding of the research, the firestorm in the press was tremendous. The headlines that vitamin D is detrimental to health took over, and the measured statements, including a need for a better understanding of the potential detrimental effects of monthly dosing and the need to confirm the results with daily dosing, were ignored.  
This week we are providing you with the information you need to better understand the research out there, and how to see beyond the headlines found in the mainstream press. Please help spread the truth - that vitamin D is safe, and should be received daily.

Carole Baggerly
Director, GrassrootsHealth
A Public Health Promotion & Research Organization
Moving Research into Practice NOW!

Vitamin D Controversy in the News 

New Study on Falls

A new paper from Bischoff-Ferrari, et al., published last week, studied 200 home-dwelling men and women, over the age of 70, in Zurich, Switzerland. The purpose of the study was to assess whether vitamin D prevented falls in the elderly. The participants were divided into three groups which received monthly doses of vitamin D: 24,000 IU; 60,000 IU; or 24,000 IU of vitamin D3 plus 300 μg of calcifediol (25-Hydroxy vitamin D3). 
Previous research studies on vitamin D and the elderly have found that a higher level of vitamin D prevented falls. But this study found differently. They found that while all groups increased their vitamin D levels, the higher vitamin D supplement groups, and those who achieved the highest 25(OH)D status, had more falls than the lowest group.

Bischoff-Ferrari stated in her discussion, "the physiology behind a possible detrimental effect of a high monthly bolus dose of vitamin D on muscle function and falls remains unclear and needs further investigation." Also, her final conclusion was not that vitamin D would not help seniors, but that high monthly bolus dosing was not the right approach. Instead, she proposes a new study using daily dosing.

In Defense of Vitamin D

While the paper from University Hospital Zurich has received a lot of press, the results of that trial do not surprise us at GrassrootsHealth as it might have several years ago. More information is now known about the importance of daily dosing versus monthly dosing than was known at the time the study took place. In order to prevent falls, you need strong muscles in addition to strong bones. For vitamin D to be effective in aiding muscle strength, stability and for general disease prevention you need to take it daily - not monthly.

In an effort to help evaluate research, what constitutes an effective study and what constitutes an ineffective study, Drs. Bruce Hollis and Robert Heaney joined together for a presentation which we will share with you.

Daily vs. Monthly Dosing

Dr. Bruce Hollis Bruce Hollis, PhD, of the Medical University of South Carolina has researched vitamin D and its effects on both the endocrine (skeletal) and autocrine (disease reduction and immune control) systems. He has found that that while 25(OH)D, the vitamin D metabolite that is measured in the blood as a marker of vitamin D status and is important for the endocrine system, has a half-life of 3-4 weeks, vitamin D3 has a half-life of only 24 hours. This distinction is important because it is the vitamin D3 delivered directly to the tissues of the body through the autocrine system that allows those tissues to convert the vitamin D3 to its active form as needed to help regulate cellular functions.  In order to achieve positive results for muscle strength or preventive health - you need to keep vitamin D in your autocrine system - you need to take it daily.

Please watch this webinar if you would like more detail. Hollis thoroughly explains how vitamin D supplementation is processed by both the endocrine and autocrine systems. He reviews clinical trials that have had success or failure and correlates their results with their dosing strategy. After watching this webinar you will understand why the high monthly doses did not help the elderly in the Zurich study.

Watch Webinar
Read summary of webinar in past newsletter

Effective vs. Ineffective Clinical Trials

Robert Heaney, MD, has spent much of his career doing research on vitamin D and other nutrients. He recently published a paper with Guidelines for nutrients (see sidebar). In order to have an effective vitamin D study you need:
  1. An understanding of how dosing affects the physiological systems - for vitamin D this means daily dosing for any non-skeletal body function studies.
  2. Basal nutrient status must be determined and used as an inclusion criterion - this means that when designing vitamin D studies you need to start with deficient people (< 20 ng/ml) to show a positive result.
  3. The change in intake must be large enough to change nutrient status meaningfully - meaning for vitamin D they should aim for large daily doses in at least one group.
  4. Change in status must be quantified - for vitamin D studies to be valid the difference in 25(OH)D from the baseline level to the final level as a result of treatment must be measured.
  5. Change in nutrient status, not change in intake, must be the independent variable in the hypothesis - for vitamin D this means analyzing the study results based on the change in measured 25(OH)D levels rather than just assigned dosage groups.
  6. Co-nutrient status must be optimized - i.e. for vitamin D studies subjects also need adequate Calcium, Magnesium and protein consumption.
  7. An understanding of the nutrient response curve to be able to define the appropriate amount of the nutrient that reduces risk - for a valid study you need to test over the range of the curve where you expect response changes, for vitamin D this is typically somewhere between 10 ng/ml - 60 ng/ml.
Below is an analysis of the Zurich study using the criteria Robert Heaney defines in his paper, Guidelines for optimizing design and analysis of clinical studies of nutrient effects.

Click to Expand

If you want to understand this information further we recommend you watch this presentation from our last seminar, Design Components of Interventions/Studies of Vitamin D.

Watch Video

Editor's Letter 
Susan Siljander 
Marketing Director, GrassrootsHealth

One of the strengths of GrassrootsHealth is its relationship with many vitamin D researchers. This study, and there will be others, is well known within the vitamin D research community - the scientists talk to each other. Most of our researchers knew about this study, the seemingly negative outcome, and were not at all surprised.

Also, keep in mind that studies have a long lead time. This study, while published this month, started recruitment in 2009 and probably was defined in 2008 or early 2009 as the author pursued funding. Much less was known about vitamin D at that time, it was thought that intermittent dosing was perfectly adequate (and easier for patient compliance).

With the amount of research out in the world today, there will always be negative and positive findings, but so much depends on the details of the research design. Please continue to help spread the word about the positive effects of vitamin D.

Thank you,

Susan Siljander
Marketing Director, GrassrootsHealth
A Public Health Promotion & Research Organization  
Moving Research into Practice NOW!
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Your participation in this project provides information for your answers to D questions and helps fund the GrassrootsHealth projects.

Dr. Cedric Garland

In the News...

People with low sunlight exposure and vitamin D deficiency at greater risk of developing leukemia

Cedric Garland, Dr PH FACE
UCSD School of Medicine
News Medical
January 7, 2016

Study finds that persons residing at higher latitudes, with lower sunlight/ ultraviolet B (UVB) exposure and greater prevalence of vitamin D deficiency, are at least two times at greater risk of developing leukemia than equatorial populations.

Vitamin D Controversy 

The Paper that started the recent controversy:

Monthly High-Dose Vitamin D Treatment for the Prevention of Functional Decline
Bischoff-Ferrari et al.
JAMA Internal Medicine
January 4, 2016

Summary of the Paper:

Taking Vitamin D May Not Reduce Risk of Falls
Time Magazine online
January 4, 2016


Vitamin D Supplementation and Increased Risk of Falling - a Cautionary Tale of Vitamin Supplements Retold
Cummings et al.
JAMA Internal Medicine
January 4, 2016

Guidelines for optimizing design and analysis of clinical studies of nutrient effects
Robert P. Heaney, MD
Creighton University
December 2013
Read paper

How to Optimize Vitamin D Supplementation to Prevent Cancer, Based on Cellular Adaptation and Hydroxylase Enzymology
Published in Anticancer Research, 2009
Reinhold Vieth, PhD
University of Toronto
Mount Sinai Hospital, Toronto
Read Paper

Seasonal periodicity of serum vitamin D and parathyroid hormone, bone resorption, and fractures: the Geelong Osteoporosis Study

Published in the Journal of bone and mineral research, 2004
Julie A Pasco, PhD, et al.
University of Melbourne, Australia
Read Paper

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