It is a sad state of affairs when a news piece is done on research and only the headline is discussed. What about the details? Do researchers painstakingly crunch numbers, follow diligent statistical guidelines, have multiple editions reviewed by multiple people – only to have one sentence pulled out and reported on?
In a recent article in The New Daily, an Australian paper, a headline stated there was ‘no case’ for vitamin D supplementation in pregnancy. That could lead one to believe that vitamin D provides no benefit to pregnancy at all.
Is that indeed that the conclusion published in the research paper?
Seven positive outcomes to vitamin D supplementation during pregnancy were included in the paper:
- Increased vitamin D levels in the mother and the cord blood (infant blood was not reported)
- Increased the mean birth weight
- 40% reduction of the incidence of ‘small for gestational age’ – which is a condition that leads to many future health conditions and potentially longer hospital stays at birth
- 20% reduction in the child’s wheezing by age 3 – a measure of reduction in asthma for children
- 40% reduction of gestational diabetes
- 18% reduction in preeclampsia
- 17% reduction in gestational hypertension
Are these things not important? If you were to tell the pregnant mother that vitamin D could improve these things – what would she do? How about if the paper reported TWICE that vitamin D was completely safe to mother and child?
What did this paper find vitamin D did not help with?
Preterm birth. The researchers found that preterm birth levels were the same with or without vitamin D. But, they did not include a pre-eminent paper on preterm birth in their analysis. It was a randomized trial, with 257 women, but since this trial did not use a control group receiving vitamin D supplementation of 600 IU/day or less, it was not allowed in the meta-analysis. In this paper, published in the American Journal of Obstetrics and Gynecology in 2013, the authors reported that preterm birth was inversely associated with vitamin D levels just before delivery.
Problem with Meta-Analysis
Within the ‘Discussion’ section of the paper the authors explain some problems with conducting a meta-analysis such as they did including 1) most of the trials were very small and 2) many trials did not keep data on clinical outcomes of the baby (i.e. low birth weight) or the mothers (i.e. preeclampsia).
The authors also discussed inherent problems of nutrient trials. Dr. Robert Heaney, former Research Director of GrassrootsHealth, wrote a paper to address these common problems with randomized controlled trials involving nutrients. The first two criteria in the list below were highlighted in the paper as a problem with many of the trials included in their meta-analysis.
Dr. Heaney’s criteria for a proper nutrient trial
- Nutrient status must be measured, used as an inclusion criterion for entry into the study, and recorded in the report of the trial. In other words vitamin D levels taken at the start and end at a minimum and used as part of the analysis.
- The intervention must be large enough to change nutrient status and be quantified by analysis. In other words, go from a deficient to sufficient vitamin D status.
- The change in nutrient status must be measured and reported.
- The hypothesis to be tested must be that a change in nutrient status (not a change in diet) produces the sought-for effect.
- Conutrient status must be optimized in order to ensure that the test nutrient is the only nutrition-related, limiting factor in the response. This is important because nutrients have pleotropic effects.
What else is missing from the misleading news headline?
GrassrootsHealth published a combined analysis in 2016 with data from two randomized controlled trials and compared them to data from the March of Dimes in the same region. The analysis was done by vitamin D levels, not dosage groups. This research found a 57% reduction in preterm birth for women who achieved 40 ng/ml (100 nmol/L) or more before delivery as compared to women with vitamin D levels less than 20 ng/ml (50 nmol/L). This paper wasn’t included because it isn’t a randomized controlled trial, it was an analysis of trial data.
Another major piece of evidence that was missing was the 2017 paper published in PLOS ONE that analyzed the data of 1,064 women on a vitamin D protocol at the Medical University of South Carolina. Again, this paper couldn’t be included in the meta-analysis because it was not a randomized controlled trial. It was a field trial, implementing the results of a definitive randomized controlled trial (the 2013 study mentioned above) done at the Medical University of South Carolina. EVERY pregnant woman received vitamin D care, because the Medical University of South Carolina was changing their standard of care based on the evidence from their randomized controlled trial. The 2017 analysis was done by vitamin D level, and found that women who achieved vitamin D levels of 40 ng/ml or higher close to delivery had a 60% lower risk of preterm birth when compared to those with levels under 20 ng/ml.
These were not included in the meta-analysis because of the rules placed on the analysis by the authors. But is that the only way to do a meta-analysis? Is that the only way to analyze data on vitamin D and pregnancy?
In a time when preterm births continue to rise, along with healthcare costs, it is time to listen to reason and apply principles that are nutritionally sound, inexpensive, and demonstrated.
What does it take to act?
- Are you pregnant? Test your vitamin D levels immediately and use our information to get above 40 ng/ml (100 nmol/L) as soon as possible.
- Know someone who is pregnant? Send them this information and to our web page on vitamin D and pregnancy.
Resources used in news headline
Vitamin D supplementation during pregnancy: state of the evidence from a systematic review of randomised trials
Roth et al.
‘No case’ for vitamin D pills in routine pregnancy: Australian Medical Association president
The New Daily
December 3, 2017
Other Vitamin D and Pregnancy Resources
A randomized trial of vitamin D supplementation in 2 community health center networks in South Carolina
Carol Wagner et al.
American Journal of Obstetrics & Gynecology
Post-Hoc Analysis of Vitamin D Status and Reduced Risk of Preterm Birth in Two Vitamin D Pregnancy Cohorts Compared with South Carolina March of Dimes 2011 Rates
Carol Wagner et al.
Journal of Steroid Biochemistry & Molecular Biology
Maternal 25(OH)D concentrations ≥ 40 ng/ml associated with 60% lower preterm birth risk among general obstetrical patients at an urban medical center
Sharon McDonnell et al.
How to Conduct Proper Nutrient Research
Guidelines for optimizing design and analysis of clinical studies of nutrient effects
Robert P. Heaney
What Does it Take YOU to Get Your D to 40 ng/ml (100 nmol/L)?Did you know your health could be greatly affected by making sure you have a vitamin D level of at least 40 ng/ml (100 nmol/L)? Help us help you.
STEP 1 - Do you know what your vitamin D level is? If not, be sure to test today to find out.
STEP 2 – Determine your target level. Are you at your target level? Experts recommend a level of at least 40-60 ng/ml (100-150 nmol/L).
STEP 3 – Need to boost your level? Use the D*calculator to see how much vitamin D it may take to reach your target. Opt for the Loading Dose for a quicker boost.
STEP 4 – Optimize how your body absorbs and utilizes vitamin D with co-nutrients and these simple steps.
STEP 5 – Re-Test! This is an important step to make sure you have reached your target level, and to ensure you are not taking too much! Re-testing after 3-4 months is recommended.
STEP 6 – Adjust, Repeat…
Give your immune system the nutrients it needs to support a healthy you and protect yourself from unnecessary diseases, especially COVID-19.
The first Randomized Controlled Trial on vitamin D and COVID-19 has shown a 96% lower risk of ICU admission for those receiving vitamin D (as 25(OH)D to quickly boost vitamin D blood levels) along with the standard treatment, compared to those receiving standard treatment alone.
These results support many previous observational studies showing a relationship between vitamin D levels and intake and COVID-19 severity.
GrassrootsHealth Nutrient Research Institute has launched the new Immune Boost project with the use of our myData-myAnswers nutrient health system that nearly 15,000 people are already using for their health. Specific markers that influence immune health are suggested for testing as part of this project including:
- Vitamin D
- Omega-3 Index
- Essential elements magnesium, selenium, and zinc
Our goal is to demonstrate how one can use the Nutrient Research Model established by Dr. Robert Heaney to show the effect of vitamin D serum levels of at least 40 ng/ml (100 nmol/L) on risk reduction for all ethnicities in the population. Status and intake of other nutrients will also be analyzed for any type of relationship to immune status and symptom severity. Join the project today!
Please let us know if you're interested in helping sponsor this project.
Through GrassrootsHealth Nutrient Research Institute, you can also test your essential elements magnesium, copper, zinc and selenium, toxins such as lead, mercury and cadmium, as well as your omega-3 levels, inflammation levels and thyroid stimulating hormone (TSH) level. Find out your levels today! Log on to the test selection page (click the link below) to get your tests and see for yourself if your levels can be improved.
Make sure you track your results before and after, about every 6 months!
How can I track my nutrient intake and levels over time?
To help you track your supplement use and nutrient levels, GrassrootsHealth has created the Personal Health Nutrient Decision System called
For each specific supplement, you can track what days you take it, how much, and many other details. This will help you know your true supplemental intake and what patterns of use work for you to reach and maintain optimum nutrient levels. Check it out today!