The research team says its results fail to explain why African Americans, who are more likely to be vitamin D deficient, also suffer from higher rates of stroke, but apparently not due to lack of vitamin D.
It is possible that the number of fatal strokes recorded in blacks might simply not have been statistically sufficient to find a relationship with vitamin D deficits.
Science Daily reports:
"Nearly 8,000 initially healthy men and women of both races were involved in the latest analysis ... Among them, 6.6 percent of whites and 32.3 percent of blacks had severely low blood levels of vitamin D, which the experts say is less than 15 nanograms per milliliter."
Optimizing your vitamin D levels is an incredibly powerful way to have a major impact on your health. Among the many benefits that research is revealing, this latest study shows that low levels of vitamin D double your risk of stroke, which is the third leading cause of death in the United States.
This adds to past research released earlier this year that also found vitamin D deficiency is associated with arterial stiffness, a risk factor for heart disease and stroke. A separate study from Finland also found that those with the lowest vitamin D 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.
What is a Stroke?
Strokes are sometimes referred to as "brain attacks" (instead of "heart attacks") because they occur when a blood clot blocks an artery or blood vessel, cutting off blood flow to your brain. When this occurs, brain cells die and brain damage can occur.
The reason why strokes can be so devastating is that they often occur without warning, and the longer your brain goes without oxygen, the greater your risk of lasting damage. This is one area where emergency medicine excels, as there are emergency medications that can dissolve a blood clot that is blocking blood flow to your brain.
In order to be effective, however, you typically need to get help within one hour. So if you notice any of these signs of stroke, you should get help right away:
- Sudden trouble walking (dizziness, loss of balance, etc.)
- Sudden confusion
- Sudden numbness or weakness (especially on one side of your body only)
- Sudden trouble seeing
- Sudden severe headache
Clearly, in the case of strokes (and most disease), prevention is your best option, and optimizing your vitamin D levels is one strategy you can take.
Why Is Vitamin D Useful for Strokes?
Vitamin D has beneficial effects far beyond the bone benefits that are typically touted. 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.
Every 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. So far, scientists have found about 3,000 genes that are upregulated by vitamin D.
Not only is vitamin D known to help reduce your risk of arterial stiffness, a major risk factor for stroke, but it can also:
- Increase in your body's natural anti-inflammatory cytokines
- Suppress vascular calcification
- Inhibit vascular smooth muscle growth
Steps for Optimizing Your Vitamin D Levels
Currently, the conventional RDAs for vitamin D 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.
Ideally, your body will make all the vitamin D you need from safe sun exposure or a safe tanning bed. But if you are not able to get sun exposure on a regular basis (and the exposure must be on large portions of your skin, not just your face or hands), you may need to supplement with oral vitamin D3.
In this case 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. If you've never had your levels tested, I strongly suggest you make it a priority to do so.
Vitamin D deficiency is widespread in the United States, where the late winter average vitamin D is less than 20 ng/ml -- a very serious deficiency state. It's estimated 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.
You can have your blood tested by your physician (be sure you get the correct test called 25(OH)D, or 25-hydroxyvitamin D), or if you're interested you can join the D*action study and have your levels tested through them. There is a $60 fee each 6 months for your sponsorship of the project, but you can get a 15 percent discount by entering "Mercola" on your order form.
Most likely, you will need to have your levels tested multiple times to ensure you're taking the right dose of vitamin D – or getting sufficient sun exposure – to keep your levels where they need to be. For more information, I encourage you to watch my free one-hour vitamin D lecture to find out what your vitamin D levels should be and how to keep them optimized for your health.
What Else Can You do to Help Prevent a Stroke?
Up to 80 percent of strokes are preventable, according to the National Stroke Association, so what can you do to lower your risk? Conventionally speaking, many of the same risk factors that increase your risk of heart disease also increase your risk of stroke, and these include factors like:
- High blood pressure
- High triglycerides and elevated homocysteine levels
- Low levels of HDL (good) cholesterol and high levels of LDL (bad) cholesterol
So, as with your heart, eating unprocessed, natural foods, exercising and keeping your weight at a healthy level will help to reduce your risk of stroke. Also high up on the list of keys to preventing a stroke is to get a handle on your stress levels as the more stressed you are, the greater your risk.
As an example, a study published in the journal Neurology found that psychological distress will greatly increase your risk of suffering a stroke. The researchers actually found that for every notch lower a person scored on their well-being scale, their risk of stroke increased by 11 percent.
Not surprisingly, the relationship between psychological distress and stroke was most pronounced when the stroke was fatal.
So while optimizing your vitamin D levels and leading a healthy lifestyle with nutritious food and regular exercise are important, you'll want to be sure you tend to your emotional health as well.