VDC test kit slider
VDC test kit slider
sperti logo 1
Text size A A A
High contrast on off

Information on the latest vitamin D news and research.

Find out more information on deficiency, supplementation, sun exposure, and how vitamin D relates to your health.

New study finds both high and low vitamin D levels associated with increased cardiovascular disease mortality

A recent study published in the Journal of Clinical Endocrinology & Metabolism discovered a J-shaped association between vitamin D levels and mortality caused by cardiovascular disease.

In 2013, Dr. Christopher Sempos and colleagues reported a J shaped curve for total mortality and baseline vitamin D levels.

Since cardiovascular disease is the leading cause of death globally, the same research team wanted to determine the relationship between vitamin D levels and mortality specific to cardiovascular disease.

The researchers analyzed data from the Copenhagen General Practitioners Laboratory (CopD). The CopD database contains data from 247,574 citizens from the Copenhagen area from 2004 to 2010. This data included vitamin D measurements and causes of death.

Over the span of seven years, 16,645 participants died, with a total of 5,454 individuals dying from cardiovascular disease.

The researchers evaluated the relationship between mortality and vitamin D levels. Here is what they found:

  • A vitamin D status of 28 ng/ml was associated with the lowest cardiovascular disease mortality risk.
  • Among individuals who died from cardiovascular disease, 78.2% had levels below 28 ng/ml.
  • Those with vitamin D levels around 4.8 ng/ml were 2.0 times more likely to die from cardiovascular disease than those with vitamin D levels of about 28 ng/ml.
  • Those with vitamin D levels of about 50 ng/ml were 1.3 times more likely to die of cardiovascular disease than those with levels around 28 ng/ml.

The researchers concluded,

“Both low and high serum 25-hydroxyvitamin D levels were associated with increased cardiovascular disease mortality as well as mortality from stroke and acute myocardial infarction.”

This study proposes interesting findings that should not be ignored; however, they should be interpreted carefully. First of all, as with any observational study, this study does not prove causation. Also, vitamin D levels were only measured once over the span of seven years. Levels could have easily fluctuated over this long duration.

A possible explanation for these puzzling results could be that 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, the average age of the participants was 51.

Further observational studies should measure vitamin D levels throughout the study, beginning at an early age to provide more insight.


Durup D., et al. A reverse J-shaped association between serum 25- hydroxyvitamin D and cardiovascular disease mortality – the CopD-study. Journal of Clinical Endocrinology & Metabolism, 2015.

  About: Amber Tovey

Amber is the Program Manager for the Vitamin D Council. Her responsibilities include writing articles, editing, fundraising and brainstorming ways for the VDC to grow. Outside of work, she loves to enjoy the beautiful hills, beaches and sunshine in the Central Coast of California.

13 Responses to New study finds both high and low vitamin D levels associated with increased cardiovascular disease mortality

  1. This does not prove causation.
    Many scientists speculate that people who were not healthy had taken lots of supplements, including vitamin D. They had a higher level of vitamin D but their lack of health resulted in earlier death.
    That is one of 10 speculations so far

    Log in to Reply
  2. D-fiant says:

    With only one vitamin D test in seven years I find it hard that they could prove anything?

    Log in to Reply
  3. Out of over 10,000 people tested in 10 years, only a few, and I mean a few, have been over 50 ng.who weren’t taking Vitamin D. A fisherman, a gardener, and an outdoor walker of 6 miles a day all year long. So it would appear that these levels of over 50 ng were taking supplements. Not many people were taking vitamin D supplements in 2004 when the study started. Were the over 50 ng people taking vitamin D supplements because they were ill with heart disease and someone told them to take it?. This could have been answered by just a simple questionnaire but apparently this wasn’t looked into.
    Robert Baker MD Cherry Hill, NJ

    Log in to Reply
  4. Doctorsh says:

    VitD does not act alone.
    We should be measuring over time not just Vitamin D, but also VitK2 and other factors involved in inflammatory endothelium.
    Also the single bullet theory that VitD by itself prevents heart disease is as accurate as cholesterol alone causes heart attacks.

    Log in to Reply
  5. BudsD3 says:

    What is also not reported here is the level of the vitamin Bs and in particular vitamin B6 and B12 as well as niacin. In the recent work of Dr. Stasha Gominak as seen on her website, the optimal level for D seemed to be 60-80 ng though some all percentage of clients seemed to respond better at lower levels. The gut biome appeared as important as the D levels as they appeared to synergizing one another. Her 3 talks can also be heard in Dr. Steven Park’s site who is a professor at Einstein Medical and Montifiore Hospital center in NYC

    Log in to Reply
  6. BudsD3 says:

    In addition, the specifics of the efficiency of the breathing rate of these persons was not monitored. That rate can be significantly influenced by D levels and vice versa as sleep can be greatly enhanced by proper day time nasal breathing rather than a predominance of mouth breathing which is so fetremtsl in numerous ways to health and oral development

    Log in to Reply
  7. The only way most people Denmark have higher vitamin D levels is that they were tested during the summer months or they are supplementing. My guess is that if they are supplementing, it is probably cod liver oil as other forms of vitamin D have been difficult to get there. A similar Danish study in 2012 concerning mortality was reviewed by this site and discussed the possibly issues with the study. https://www.vitamindcouncil.org/blog/high-and-low-vitamin-d-levels-cause-mortality/ specifically talked about vitamin A from cod liver oil.

    Log in to Reply
  8. The problem with this and many related studies is that they did not ask any questions about vitamin D supplementation. Those with the highest vitamin D levels had to be taking supplements. However, starting to take supplements late in life cannot erase the adverse effects of low vitamin D earlier in life for chronic diseases that take years to develop. I have submitted a letter to the editor of the journal pointing this out. In support of my idea, the women in this study had higher risk of death at higher vitamin D levels than did men, which is consistent with elderly women being more likely to take vitamin D supplements. A few men might get higher vitamin D levels from outdoor work.

    It is unfortunate that this study is getting all the publicity it is. Perhaps in the next newsletter the problems with this study can be addressed.

    Log in to Reply
  9. tanlines says:

    Here’s what Dr Veith thinks of the “U” or “J” Shaped curves in Vitamin D. His hypothesis is high latitude and fluctuation along with the diminishing numbers at higher doses, just as the statistics in the paper in question shows. CLICK ON LINK, Not Image to start video on topic. https://youtu.be/MIDWA9-cGdY?t=25m31s

    Log in to Reply
  10. pheppel says:

    It is not so easy to dismiss this study as just observational, since the vast majority of studies showing benefit from higher vitamin D levels are also observational. I think the critical thing that is missing from vitamin D observational studies is the vitamin K2 and calcium interplay. There are studies which independently show that calcium supplementation increases the risk of heart disease. Vitamin D increases calcium absorption and it increases the production of calcium binding proteins. For calcium binding proteins to be effective they need to be carboxylated through a process that uses vitamin K2. Calcium binding proteins (osteocalcin and MGP) move calcium into bone and out of soft tissue like arteries. Calcium deposition measured in arteries is becoming an accepted measure of cardiovascular disease risk (reference CAC scoring). The vitamin K2 carboxylation process is a double process needed to activate the calcium binding proteins, so, if for example, increased vitamin D levels double the production of calcium binding proteins, but vitamin K2 levels to not increase proportionally, you could end up with half as many activated calcium binding proteins. Example: Assume perfect balance between vitamin K2 and calcium binding proteins, each calcium binding protein takes two units of K2 and all calcium binding proteins are fully functional. Now double the number of calcium binding proteins and randomly allocate the original amount of K2, one quarter would get two units of K2, one half would get 1 unit and one quarter would get none. Only the quarter with 2 vitamin K2 units would be functional, so by doubling calcium binding proteins you halve the number of functional proteins. Increased vitamin D levels increase calcium binding proteins. Without increased K2 that could result in less effective calcium regulation accounting for both the vitamin D results and the calcium results with respect to heart disease.

    Log in to Reply
  11. John Cannell, MD says:

    This study is confounded with retinol. People in Denmark take cod liver oil , which will raise the D levels and cause subclinical vitamin A toxicity. High intakes of retinol are associated with increased mortality.

    Log in to Reply
  12. Rebecca Oshiro says:

    Dr. Holick addressed this issue at his talk in San Diego in December 2014. He shared evidence from another J-shaped curve study where there was actually data to show that the higher 25(OH)D levels were indeed in those who received prescription D. Those most likely to receive this kind of supplementation were those most likely to be treated for other health conditions by their doctor. You find out you’re sick with cancer or heart disease and then you start taking a D supplement and then you die. The D didn’t cause death…..the comorbid condition did.

    Log in to Reply
  13. Apparently extra magnesium is needed with vit D supplementation which may reduce mg availability to heart etc. And mg levels are typically low anyway. Combine that with the extra calcium absorption from high dairy consumption, and low vit C levels, it is not surprising that vascular health is worse with high D from any source. Also it would be interesting to see the self health assessment of participants and exercise levels. I’ve heard of too many long distance runners dropping dead, or having heart issues, needing stents. High exercise levels generate high levels of free radicals.

    Log in to Reply