Last week, Denmark news announced that high levels of vitamin D can lead to a higher risk of death from cardiovascular disease. Please forward this newsletter to your friends to help set the record straight. Our scientists tell us a different story - that vitamin D levels within 40-60 ng/ml do not increase your chance of getting cardiovascular disease!

Study shows increased mortality with high vitamin D levels

A study published February 17, 2015 by Durup et al. reported "A reverse J-shaped association between serum 25-hydroxyvitamin D and cardiovascular disease mortality - the CopD-study." This backwards J-shape implies that the lowest risk of mortality is in the middle range of vitamin D (70 nmol/L or 28 ng/ml) with an increased risk at low levels (12.5 nmol/L or 5 ng/ml) and a slight increased risk at high levels (125 nmol/L or 50 ng/ml).

The study used data from 247,574 subjects from the general practice sector. They had one blood sample from each person but followed the results for seven years, from 2004 to 2011. They looked at mortality rates from cardiovascular disease and compared this to the vitamin D level they had for that person at the beginning of the study (2004).

GrassrootsHealth scientists refute this conclusion 

GrassrootsHealth stands behind its recommendation of 40-60 ng/ml circulating 25(OH)D concentrations for preventive health. GrassrootsHealth scientists believe there is no J- or U-shaped curve, instead research shows a big decline, followed by gradual decline, and leveling off.

Dr. Cedric Garland et al. examined the relationship between serum 25-hydroxyvitamin D (25[OH]D) and all-cause mortality in his paper "Meta-analysis of all-cause mortality according to serum 25-Hydroxyvitamin D". The study searched biomedical databases for articles that assessed 2 or more categories of 25(OH)D from January 1, 1966, to January 15, 2013. They identified 32 studies and pooled the data. The outcome? "There is no acceleration of the curves toward higher mortality at higher serum 25(OH)D levels."

"Another study (Grober, Reichrath, & Holick - Nutrients 2015) specifically looked at mortality for individuals with 25(OH)D values above 50 ng/ml and 70 ng/ml. No increase in mortality was found. " - Dr. Robert Heaney

Possible explanation for outcome: The people with "high" (50 ng/ml) vitamin D levels were sick and on medication for vitamin D deficiency

In the Durup et al. study, they used one sample of vitamin D, from 2004. In 2004, much less was known about the association of vitamin D with improved health. Therefore only those who were under a doctor's care, and receiving prescription doses of vitamin D2, would have high vitamin D levels. It is safe to assume that even though their vitamin D levels were relatively high - those increased levels came too late. They still died of cardiovascular disease, but a higher vitamin D level was not the cause - just an outcome of the treatment.  

"Dosing very sick people with vitamin D is always worth a try, but the effort often comes too late in the natural history of the disease in some patients, producing potentially biased results such as those recently reported by Durup et al. " - Garland

"The high extremes are the few percent of people who were taking D supplements for an indication that would put them at higher risk for mortality." - Dr. Edward Giovannucci

Dr. John Cannell, founder and Executive Director of the Vitamin D Council, says the following, "...healthy vitamin D levels are important to maintain throughout life, beginning at an early age. A recent study found that vitamin D status during adolescence affects the risk of adult atherosclerosis, suggesting that vitamin D levels play a vital role in heart health starting at an early age. In this study (Durup et al.), the average age of the participants was 51."

Dr. Michael Holick cites a paper he co-authored using lab data from Quest Diagnostics. In this study he found that during the late 20th century if a subject had high values of circulating D, then they also had D2 in their system - proving that they were under a doctor's care and taking high doses of pharmaceutical D2 to correct a deficiency or disease.

Interview with Dr. Michael Holick

For those of us who are more visual, here is a great skype interview with Carole Baggerly and Dr. Holick.  

"Should they be worried?" - Baggerly

"No!" - Holick

This interview does a great job explaining why a "high" value of 50 ng/ml in 2004 would actually indicate that the subject was under medication for a disease and/or vitamin D deficiency. It also explains the sampling they took and why if this was correct, we would be extinct today.  

Extinct? Yes... if high vitamin D levels caused cardiopulmonary distress, then our ancestors who lived on the plains and had a blood level of about 50 ng/ml from birth would have all had heart attacks and died.  

"If this were true then people in Africa and other southern sunny climates should be dropping dead from heart attacks left and right!" - Dr. Bruce Hollis

What does the D*action data say?

Another compelling argument is the D*action data. In this cohort are many people (7000+) who have raised their vitamin D levels gradually to 40-60 ng/ml, using D3 supplementation or sun exposure. Looking at our data we notice that with an average vitamin D level of 43 ng/ml, our D*action participants have an 84% lower prevalence of cardiovascular disease (CVD). 

The following graph (notice it is almost flat, not a U or a backwards J) shows our D*action participants risk of cardiovascular disease by serum level from 5 to 200 ng/ml!  

Practical advice from an expert

"It would not be wise for anyone to reduce vitamin D3 dosage in response to the recent Durup et al. paper for another reason. A high serum 25(OH)D, which is usually in the form of 25(OH)D3, is associated with lower incidence of breast, colon and lung cancer, adult leukemia and other serious cancers, multiple sclerosis, type 1 diabetes, fractures and falls, among other very major public and personal health benefits.  Reducing or stopping vitamin D3 supplementation would raise the risk of these serious cases to the high level of people who are deficient (i.e., who have 25(OH)D < 40-60 ng/ml). A precancerous lesion that is being held in check by vitamin D could worsen or emerge within weeks or months if the vitamin D3 intake and serum 25(OH)D3 concentration D is reduced. " - Garland