Is Vitamin D Associated With Heart Disease Risk?
Author: Dr. Stephen Chaney
Not too many years ago, we thought of vitamin D as affecting bone density and little else. Then we discovered that almost every cell in our body has vitamin D receptors. This has lead to research suggesting that vitamin D affects our health in many ways that were unimaginable only a couple of decades ago.
For example, low vitamin D levels are associated with increased risk of heart disease. The linkage between vitamin D and heart disease has not been proven. Nor do we know the mechanism. However, this has lead to ongoing research asking if there is any relationship between vitamin D and cholesterol metabolism.
The answer appears to be yes. Several studies have suggested a correlation between low vitamin D levels and elevated total cholesterol, LDL cholesterol, and triglycerides – all risk factors for heart disease.
The next question is how early in life is this correlation found. Again, some studies have suggested that the same correlation between low vitamin D and high levels of unhealthy lipids are found in teens. But, what about pre-teens, children who haven’t gone through puberty yet? That’s what this study was designed to determine.
How Was The Study Done?
The current study was based on data collected from 419 children, ages 6-8, in the Physical Activity and Nutrition in Children (PANIC) Study in Eastern Finland. This was a lifestyle study that collected information on body weight, diet, and activity levels.
Fasting blood samples were also collected and analyzed for blood lipid levels (total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides) and for 25-hydroxyvitamin D (25(OH)D), which is considered the most accurate measure of vitamin D status. The National Institutes of Health considers:
- <30 nmol/L of 25(OH)D an indicator of vitamin D deficiency.
- 30 to <50 nmol/L 25(OH)D an indicator of vitamin D insufficiency.
- ≥50 nmol/L 25(OH)D an indicator of adequate vitamin D status.
To put this study in perspective, vitamin D status is a major concern in Finland because of its proximity to the Arctic Circle. There is little sunlight in the winter, and, although the days are long in the summer, the sun is weak. The major sources of vitamin D in the Finnish diet are fish, vitamin D-fortified fluid milk products, vitamin D-fortified fat spreads, and vitamin D supplementation. Vitamin D fortification was introduced in Finland in 2003. Vitamin D supplementation has also become increasing popular. The number of people using vitamin D supplements has increased from 11% in 2000 to 41% in 2011.
A recent study looking a vitamin D status between 2000 and 2011 found that the combination of food fortification and vitamin D supplementation has been successful at improving vitamin D status in the Finnish population, increasing average 25(OH)D levels from 48 nmol/L to 65 nmol/L.
Does Vitamin D Reduce Cholesterol In Children?
In this study the mean serum 25(OH)D in the children was 68.1 nmol/L. 20% of the children had serum 25(OH)D below 50 nmol/L, and only 4 children (1%) had serum 25(OH)D below 30 nmol/L. When 25(OH)D levels were compared with blood lipid levels:
- Higher serum 25(OH)D levels were associated with lower plasma levels of total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides.
- The association between higher 25(OH)D levels and lower blood levels of total cholesterol, LDL cholesterol, and HDL cholesterol remained after correcting for weight, physical activity, sedentary behavior, diet, daylight time, parental education, and genetic mutations known to affect vitamin D metabolism.
What Does This Mean For You?
I don’t want to overinterpret the study. Not all studies show an inverse association between 25(OH)D and cholesterol levels. Most of the previous studies have also indicated that higher 25(OH)D levels were associated increased HDL levels, while this study found higher 25(OH)D levels associated with decreased HDL levels. Much more research needs to be done.
However, this study is yet another indication that optimal vitamin D status may be important for heart health, even in young children. While the correlation between vitamin D status and heart health is not definitive at present, virtually everyone agrees that adequate vitamin D status is a good thing.
My recommendations are to:
- Get as much vitamin D as possible from vitamin D-fortified foods, oily fish, and sensible sun exposure.
- Get your serum 25(OH)D level determined and take vitamin D supplements if it is low.
The Bottom Line
A recent study of vitamin D status in Finnish children ages 6-8 found:
- Higher vitamin D status was associated with lower plasma levels of total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides.
- The association between better vitamin D status and lower blood levels of total cholesterol, LDL cholesterol, and HDL cholesterol remained after correcting for weight, physical activity, sedentary behavior, diet, daylight time, parental education, and genetic mutations known to affect vitamin D metabolism.
This study is another indication that optimal vitamin D status may be important for heart health, even in young children. While the correlation between vitamin D status and heart health is not definitive at present, virtually everyone agrees that adequate vitamin D status is a good thing.
My recommendations are to:
- Get as much vitamin D as possible from vitamin D-fortified foods, oily fish, and sensible sun exposure.
- Get your serum 25-hydroxyvitamin D level determined and take vitamin D supplements if it is low.
- Make sure your children are getting enough vitamin D in their diet and have optimal serum 25-hydroxyvitamin D.
For more details, read the article above.
These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.