By Dr. Mercola
According to a new study, vitamin D deficiency is associated with arterial stiffness, a risk factor for heart disease and stroke, in black teens. Vitamin D supplementation of 2,000 international units (IU) per day resulted in a decrease in central arterial stiffness.
In the study, 44 black teenagers were randomly assigned to receive either 400 IU of vitamin D per day (the recommendation of the American Academy of Pediatrics) or 2,000 IU of vitamin D per day.
"Study subjects taking 400 IU of vitamin D per day did not achieve vitamin D sufficiency, while their peers who took 2,000 IU of vitamin D per day on average became vitamin D sufficient."
Further, a separate report highlighted just how widespread vitamin D deficiency is, noting that a huge part of the population is deficient in this essential nutrient.
Every tissue in your body, including your brain, heart, muscles and immune system, has receptors for vitamin D, meaning that this nutrient is needed at proper levels for these tissues to function well.
According to the New York Times:
"Studies indicate that the effects of a vitamin D deficiency include an elevated risk of developing (and dying from) cancers of the colon, breast and prostate; high blood pressure and cardiovascular disease; osteoarthritis; and immune-system abnormalities that can result in infections and autoimmune disorders like multiple sclerosis, Type 1 diabetes and rheumatoid arthritis."
Low levels of vitamin D could account for the high incidence of several chronic diseases in the U.S. For example, he said, in the Northeast, where sun exposure is reduced and vitamin D levels consequently are lower, cancer rates are higher than in the South.
Arterial stiffness, a major risk factor for heart disease and stroke -- two of the most common killers in the United States -- is associated with vitamin D deficiency.
Yet when black teens -- 95 percent of whom were vitamin D deficient -- took the 400 IU of vitamin D per day recommended by the American Academy of Pediatrics, it was nowhere near enough to bring their levels into a healthy range. In this latest study, only the teens who took 2,000 IU of vitamin D a day became vitamin D "sufficient," instead of "deficient."
There are two important points to be gleaned from this finding. One, if your vitamin D levels are not optimized, you're very likely putting your future heart health and risk. And, two, if you listen to the government's recommendations about how much vitamin D you need to stay healthy you'll likely come up far too short.
Why is Vitamin D So Important for Your Heart?
Vitamin D is not "just a vitamin" that is necessary for strong bones. Rather, vitamin D is the only known substrate for a potent, pleiotropic (meaning it produces multiple effects), repair and maintenance seco-steroid hormone that serves multiple gene-regulatory functions in your body.
Each cell in your body has its own DNA library that contains information needed to deal with virtually every kind of stimulus it may encounter, and the master key to enter this library is activated vitamin D.
This is why vitamin D functions in so many different tissues, and affects such a large number of different diseases and health conditions, one of which is heart disease.
There are a number of physiological mechanisms triggered by vitamin D production through sunlight exposure that act to fight heart disease, including:
- An increase in your body's natural anti-inflammatory cytokines
- The suppression of vascular calcification
- The inhibition of vascular smooth muscle growth
Numerous research studies also show the importance of optimizing your vitamin D levels for a healthy heart:
- In a Clinical Endocrinology study, researchers found that people with the lowest average vitamin D levels had a 124 percent greater risk of dying from all causes and a 378 percent greater risk of dying from a heart problem.
- Researchers from Finland showed that when compared with the participants with the highest vitamin D, those with the lowest levels had a 25 percent higher risk of dying from heart disease or stroke. And when only stroke was looked at, those with the lowest levels had twice the risk as those with the highest.
- Women who take vitamin D supplements lower their risk of death from heart disease by one-third.
So you can see that being vitamin D deficient leads to massively increased risks for your heart -- risks that could be avoided simply by optimizing vitamin D.
Government Recommendations are Far Too Low
Right now, only 5 percent to 37 percent of American infants meet the standard for vitamin D set by the American Academy of Pediatrics, which will make them prime candidates for a slew of future health problems related to vitamin D deficiency – one of them being arterial stiffness and future heart problems.
At the end of 2008, the American Academy of Pediatrics doubled its recommended dose of vitamin D for infants, children and adolescents, raising it from 200 to 400 units per day. But research published earlier that same year revealed children may need 10 times that amount in order to receive the health benefits that optimal vitamin D levels have to offer.
That was certainly the case in the study above, where 400 IU did next to nothing to bring the teens' vitamin D levels into a healthy range.
As of right now, the conventional RDAs are only:
- 400 IU for infants, children and adolescents
- 200 IU for adults up to age 50
- 400 IU for adults aged 51 to 70
- 600 IU for seniors over 70
These are a far cry from what is actually needed for optimal health.
Based on the latest research, many experts now agree you need about 35 IU's of vitamin D per pound of body weight. This recommendation also includes children, the elderly and pregnant women.
However, vitamin D requirements are highly individual.
Your vitamin D status is dependent on several factors, such as the color of your skin, where you live, and how much sunshine you're exposed to on a regular basis. So, although these recommendations may put you closer to the level of what most people likely need, it is virtually impossible to make a blanket recommendation that will cover everyone.
The only accurate way to determine your optimal dose is to get your blood tested. Ideally, you'll want to maintain a vitamin D level of at least 50ng/ml and perhaps as high as 80-90 ng/ml year-round.
Deficiency Widespread: African Americans Most at Risk
"Most people in the modern world have lifestyles that prevent them from acquiring the levels of vitamin D that evolution intended us to have. The sun's ultraviolet-B rays absorbed through the skin are the body's main source of this nutrient.
Early humans evolved near the equator, where sun exposure is intense year round, and minimally clothed people spent most of the day outdoors."
As a result, vitamin D deficiency is widespread in the United States, where the late winter average vitamin D is only about 15-18 ng/ml -- a very serious deficiency state. Meanwhile, it's thought that over 95 percent of U.S. senior citizens may be deficient, along with 85 percent of the American public, including all ages from newborns through adulthood.
However, African Americans and other dark-skinned people and those living in northern latitudes make significantly less vitamin D than other groups; the darker your skin is, the less likely it is that you will produce adequate vitamin D levels from sun exposure alone.
In one recent study in the Archives of Internal Medicine, 97 percent of African Americans had vitamin D levels that were too low for optimal health, along with 90 percent of Mexican Americans and 71 percent of whites.
This deficiency not only raises your risk of heart problems, it also raises your risk of numerous other chronic diseases. Receptors that respond to the vitamin have been found in almost every type of human cell, from your brain to your bones, which explains why researchers keep finding health benefits from vitamin D in virtually every area they look, including:
Researchers have calculated that simply increasing levels of vitamin D3 could prevent diseases that claim nearly 1 million lives throughout the world each year!
A Simple Way to Protect Your Heart and Your Health
Fortunately, you, too, can soon be reaping the benefits that vitamin D has to offer because vitamin D deficiency is incredibly easy to fix!
I encourage you to watch my free one-hour vitamin D lecture to find out how to get your levels optimized.
In short, you will need to determine your level using a 25(OH)D, also called 25-hydroxyvitamin D, blood test, and then use a combination of safe sun exposure, a safe tanning bed and supplementation to keep your levels in the healthy range.
My recommended lab is Lab Corp, as they use the standard that all the major vitamin D studies used. Again, to get all the details you need, please watch my free vitamin D lecture. It is crucially important to your health and the health of your children. Remember, vitamin D deficiency is widespread in infants, children and teens, too, so you'll want to get their levels tested -- and optimized -- as well.
Of course, this is just one healthy move you can make for your heart -- there are others as well. In this past article I've detailed seven simple steps for a healthy heart, and they're a great starting point to keeping your heart fit and strong.