Supplement Series: Vitamin D (Part 2 of 5)
Welcome back to our 5-part expert series on Vitamin D.
In our last post, we talked about the importance of vitamin D in regulating gastrointestinal health. Today, we're going to focus on one particular topic: the relationship between Vitamin D and heart health.
It's no secret that heart disease is a leading cause of death across the globe. According to the World Health Organization, almost 18 million deaths annually are due to cardiovascular disease. 85% of those deaths were linked to heart attack and stroke which have known modifiable risk factors that could reduce your risk.[1] That's why it's so important to do everything you can to keep your heart healthy. And as it turns out, getting enough Vitamin D may be one of the best things you can do for your heart.
Vitamin D and Heart Disease
There is a growing body of evidence linking Vitamin D deficiency to an increased risk of cardiovascular disease. At the 22nd European Meeting on Hypertension and Cardiovascular Protection in 2012, researchers presented data that showed 3,000 IU of vitamin D taken daily for 20 weeks over winter could reduce central blood pressure by 6.8 mmHg in those with hypertension.[2] This can be observed in data that correlates geographic location with blood pressure and hypertension. For every 10 degrees difference in latitude, blood pressure rises by 2.5 mm Hg while the risk of hypertension increases by 2.5%.[3,4]
A 2013 meta-analysis of over 283,537 participants found that people with low levels of vitamin D were more 30% likely to develop hypertension than those with normal levels.[5]
Even if you don't have an outright deficiency, being even slightly low in vitamin D can increase your risk of cardiovascular disease. A large review of data from over 300,000 people found that raising vitamin D above 40 ng/mL could reduce all-cause mortality, and those related to cardiovascular concerns, respiratory issues, and cancer.[6]
How does vitamin D influence the heart?
Once more, we visit the function of the vitamin D receptor (VDR) which is heavily expressed by the heart and endothelium.[7] It is this expression in the vessel walls that allows vitamin D to influence the renin-angiotensin-aldosterone system and decrease blood pressure.[8]
Artaza, Jorge N., Rajnish Mehrotra, and Keith C. Norris. "Vitamin D and the cardiovascular system." Clinical Journal of the American Society of Nephrology 4.9 (2009): 1515-1522.
Beyond the heart though, we look at the impact of this important nutrient on cardiometabolic function. A patent application combining a statin medication with vitamin D is currently pending in the US system. There is interest in the combination medication because of the early research showing that this nutrient can reduce the side effects of HMG-CoA reductase inhibitors when used to treat hyperlipidemia.[9] This could be an incredibly valuable medication as statin-related side effects range from muscle inflammation and pain to death of the muscle tissue at worst.[10]
Getting Enough Vitamin D
So how do you make sure you're getting enough Vitamin D? The answer may vary depending on whom you ask but many experts agree that one way to get Vitamin D is through exposure to sunlight. Just 20-30 minutes of sunlight exposure per day should be enough to maintain healthy levels in most people, though there are countless caveats to that statement.
Of course, not everyone can get outside for 20-30 minutes every day (We’re looking at you, winter). In these cases, strategic supplementation may be necessary to ensure that you're getting enough vitamin D. The Recommended Dietary Allowance (RDA) in Canada for vitamin D is 400IU (10 µg) per day. However, many experts believe that these guidelines are too low and that most adults need 1000-2000 IU per day, especially during the winter months. A controversy came to light in 2015 after biostatisticians from the School of Public Health (University of Alberta) determined that the RDA had been miscalculated by the Institute of Medicine (IOM) that establishes the RDA for Canadians and Americans alike.[11] This error captured by the researchers was further confirmed by another team that wrote:
“Thus, we confirm the findings of these investigators with regard to the published RDA for vitamin and we call for the IOM and all public health authorities concerned with transmitting accurate nutritional information to the public to designate, as the RDA, a value of approximately 7000 IU per day from all sources. We note that this conclusion applies specifically to the IOM’s designation of 20 ng/mL as the lower bound of adequacy, and that higher values, such as that of the Endocrine Society and GRH, would mandate the higher RDA values cited above.”[12]
There's no question about it: getting enough vitamin D is vital for optimal health. While we typically think about calcium when it comes to bone health, vitamin D is just as important (if not more so). But new research is beginning to show that vitamin D may also play an important role in keeping our hearts healthy. If you're not getting enough sun exposure, talk to your care provider and consider taking a supplement to ensure that you're getting enough vitamin D for optimal health.
Stay tuned for our next blog in this series where we'll be discussing the link between Vitamin D and cognitive health.
REFERENCES
Kaptoge, Stephen, et al. "World Health Organization cardiovascular disease risk charts: revised models to estimate risk in 21 global regions." The Lancet Global Health 7.10 (2019): e1332-e1345.
Larsen, Thomas, et al. "Effect of cholecalciferol supplementation during winter months in patients with hypertension: a randomized, placebo-controlled trial." American journal of hypertension 25.11 (2012): 1215-1222.
Li, Yan Chun, et al. "Vitamin D: a negative endocrine regulator of the renin–angiotensin system and blood pressure." The Journal of steroid biochemistry and molecular biology 89 (2004): 387-392.
Vaidya, Anand, and Jonathan S. Williams. "The relationship between vitamin D and the renin-angiotensin system in the pathophysiology of hypertension, kidney disease, and diabetes." Metabolism 61.4 (2012): 450-458.
Kunutsor, Setor Kwadzo, Tanefa Antoinette Apekey, and Marinka Steur. "Vitamin D and risk of future hypertension: meta-analysis of 283,537 participants." European journal of epidemiology 28.3 (2013): 205-221.
Sutherland, Joshua P., Ang Zhou, and Elina Hyppönen. "Vitamin D Deficiency Increases Mortality Risk in the UK Biobank: A Nonlinear Mendelian Randomization Study." Annals of Internal Medicine 175.11 (2022): 1552-1559.
Chen, Songcang, et al. "Expression of the vitamin d receptor is increased in the hypertrophic heart." Hypertension 52.6 (2008): 1106-1112.
Lin, Lin, et al. "Vitamin D and vitamin D receptor: New insights in the treatment of hypertension." Current Protein and Peptide Science 20.10 (2019): 984-995.
Isaacs, Andrew. "Statin+ vitamin d combination drug and method of use." U.S. Patent Application No. 16/160,432.
Ramkumar, Satish, Ajay Raghunath, and Sudhakshini Raghunath. "Statin therapy: review of safety and potential side effects." Acta Cardiologica Sinica 32.6 (2016): 631.
Veugelers, Paul J., and John Paul Ekwaru. "A statistical error in the estimation of the recommended dietary allowance for vitamin D." Nutrients 6.10 (2014): 4472-4475.
Heaney, Robert, et al. "Letter to Veugelers, PJ and Ekwaru, JP, A Statistical Error in the Estimation of the Recommended Dietary Allowance for Vitamin D. Nutrients 2014, 6, 4472–4475; doi: 10.3390/nu6104472." Nutrients 7.3 (2015): 1688-1690.