It’s important to note that vitamin D receptors are distributed throughout the human body, including vascular smooth muscle cells, endothelium, and cardiomyocytes. Cardiomyocytes are muscle cells. Endothelium is the thin tissue that lines the interior of blood vessels and lymphatic vessels. Vascular smooth muscle cells provide structural integrity to blood vessel walls, and regulate the diameter of blood vessels by contracting and relaxing dynamically in response to vasoactive stimuli (otherwise known as blood pressure). But this alone does not prove that vitamin D can affect blood pressure.
Multiple studies have demonstrated that vitamin D can help lower blood pressure, some going back to the late 1990s. For example, in a study published in the UK medical journal Lancet, “Krause et al reported that hypertensive patients exposed to UVB radiation for 3 mo had a 180% increase in circulating concentrations of 25(OH)D and a 6 mm Hg decrease in their diastolic and systolic blood pressures, results similar to those expected if the patients had received a blood pressure medication.”1
25(OH)D, also known as Calcidiol, is what your body converts vitamin D3 – be it from diet, supplements or sunlight – into. Then Calcidiol is converted into Calcitriol, also known as 1,25(OH)2 D.
In a later study, published in Journal of Clinical Investigation, “A similar group of patients who were exposed to ultraviolet A radiation and whose circulating concentrations of 25(OH)D did not increase continued to be hypertensive throughout the 3-mo study. The exact mechanism by which UVB radiation returned the blood pressure to normal [presumably due to increased blood concentrations of 25(OH)D] in these hypertensive adults is not well understood, but the observation [made in the study “1,25-dihydroxyvitamin D3 is a negative endocrine regulator of the renin-angiotensin system.”] sheds some light on the question. They observed in a mouse model that 1,25(OH)2 D is effective in down-regulating renin and angiotensin and thereby decreasing blood pressure.”1
So, it’s the UVB radiation that our skin uses to manufacture vitamin D and decreases blood pressure, while UVA radiation is wholly ineffective. It’s interesting to note that UVA radiation is what tans the skin and causes premature aging and wrinkles, while UVB radiation is responsible for sunburns and skin cancer.
It’s also important to note the observations made in the mouse model. The renin-angiotensin system is a hormone system that helps to regulate the sodium content of our blood, arterial blood pressure and fluid balance in the body. Maintaining the sodium balance in the body is among the most essential purposes of that system, and sometimes achieving that balance requires activities that raise blood pressure.
Another study, published in the journal Circulation, also mentions renin in relation to vitamin D’s ability to decrease blood pressure. “Clinical studies have reported cross-sectional associations between lower vitamin D levels and plasma renin activity, blood pressure, coronary artery calcification, and prevalent cardiovascular disease. Additionally, ecological studies have reported higher rates of coronary heart disease and hypertension with increasing distance from the equator, a phenomenon that has been attributed to the higher prevalence of vitamin D deficiency in regions with less exposure to sunlight.”2
High Blood Pressure Consequences
Everyone knows that elevated blood pressure damages the heart and coronary arteries, which can lead to heart attack and stroke, but there are other serious consequences of persistent hypertension.
- Kidney damage
- Vision loss
- Erectile dysfunction
- Memory loss
- Peripheral artery disease
- Fluid in the lungs, brought on my pulmonary edema
Whose most at risk
As I detailed in my last post, Vitamin D Versus Diabetes, the more melanin you have in your skin the more likely you are to be vitamin D deficient. This fact also helps to explain why people of African descent, living in parts of the world that are not sunny most of the year, are more likely to suffer from high blood pressure than those with less melanin. I also mentioned the elderly and infants, for different and similar reasons. Check out that post to learn more.
Naturally decreasing high blood pressure
Although multiple studies have verified that vitamin D can decrease blood pressure, as much as some pharmaceutical drug regimens, it’s important to keep in mind that your hypertension may not be the result of a vitamin D deficiency, or there may be additional factors. If that is the case, you should not depend solely on one natural solution, such as sunbathing and/or taking vitamin D3 supplements. You would also be wise to keep an eye on your sodium intake, exercise regularly, and take steps to boost and protect your emotional health. All of these natural solutions have proven to be effective for keeping blood pressure under control.
I explain how to calculate the amount of vitamin D you need in the video ‘Vitamin D vs Disease‘.
1 Holick, Michael F. “Vitamin D: importance in prevention of cancers, type 1 diabetes, heart disease, and osteoporosis”. The American Journal of Clinical Nutrition, March 2004. Web. June 2016
2 TJ Wang, MS Pencina, SL Booth, PF Jacques, et al. “Vitamin D Deficiency and Risk of Cardiovascular Disease”. Circulation, January 29. 2008. Web. July 2016
“Why Blood Pressure Matters.” American Heart Association
“Ultraviolet B and Blood Pressure”. Lancet, August 29, 1998. Web. July 2016
“Why Blood Pressure Matters”. American Heart Association
McCoy, Krisha, MS. “The Aging Effects of UV Rays”. Everyday Health, October 12, 2009. Web. July 2016
Hall JE. “Content of blood pressure by the renin-angiotensin-aldosterone system”. Clinical Cardiology, August 1991. Web. July 2016
Mercola, Joseph, MD. “Vitamin D Can Save You from Diabetes and Dementia”. Mercola, March 9, 2015. Web. June 2016