How Vitamin C and Iron Can Help Reduce Your Risk of Stroke

Vitamin C and Iron

Story at-a-glance

  • Stroke is the fourth leading cause of death in the United States
  • Up to 80 percent of all strokes are preventable through lifestyle factors such as diet, exercise, maintaining a healthy weight, normalizing your blood sugar levels and blood pressure, and quitting smoking
  • Recent research shows that those with vitamin C deficiency are at an increased risk for hemorrhagic stroke. In an earlier study, people with high blood levels of vitamin C reduced their stroke risk by 42 percent
  • Research also suggests that iron deficiency can increase your risk of ischemic stroke if you have hereditary hemorrhagic telangiectasia, a hereditary disease that causes enlarged blood vessels in your lungs
  • Sun exposure can reduce your stroke risk both by elevating your vitamin D levels, and by inducing nitric oxide in your skin, which helps normalize your blood pressure


This is an older article that may not reflect Dr. Mercola’s current view on this topic. Use our search engine to find Dr. Mercola’s latest position on any health topic.

By Dr. Mercola

Stroke, which is akin to a heart attack in your brain, is the fourth leading cause of death in the United States.1 Obstructed blood flow to your brain is known as an ischemic stroke, which represent about 75 percent of all strokes. When an artery that feeds your brain with blood actually ruptures, it's called a hemorrhagic stroke, and this is a far more lethal situation.

Fortunately, up to 80 percent of all strokes are preventable through lifestyle factors2 such as diet, exercise,3, 4 maintaining a healthy weight, normalizing your blood sugar levels and blood pressure, and quitting smoking.

For example, research published last year5 found that if you're inactive, you have a 20 percent higher risk for having a stroke or mini-stroke (transient ischemic attack) than people who exercise enough to break a sweat at least four times a week.

Recent studies also highlight the importance of getting sufficient amounts of vitamin C and iron in your diet. Interestingly, certain weather conditions have also been linked to increased rates of stroke, and getting appropriate amounts of sun exposure can help protect against it, in more ways than one.

Getting Enough Vitamin C May Help Reduce Risk of Hemorrhagic Stroke

The first featured article6 reports the preliminary findings of a French study, which found that those with vitamin C deficiency are at an increased risk for a lethal hemorrhagic stroke. According to the article:

"'Our results show that vitamin C deficiency should be considered a risk factor for this severe type of stroke, as were high blood pressure, drinking alcohol and being overweight in our study,'" study researcher Dr. Stéphane Vannier, M.D., of Pontchaillou University Hospital in France, said in a statement.

'More research is needed to explore specifically how vitamin C may help to reduce stroke risk. For example, the vitamin may regulate blood pressure.' ...[P]ast studies have also linked vitamin C with reduced stroke risk.

A 2008 University of Cambridge study found people with high blood levels of vitamin C reduced their stroke risk by 42 percent, and a similar 1995 study in the British Medical Journal indicated elderly people with low levels of the vitamin had a greater risk of stroke."

What's the Best Way to Optimize Your Vitamin C?

The ideal way to optimize your vitamin C stores is by eating a wide variety of fresh whole foods. A number of people, primarily with the naturopathic perspective, believe that in order to be truly effective, ascorbic acid alone is not enough.

They believe the combination of the ascorbic acid with its associated micronutrients, such as bioflavonoids and other components. Eating a colorful diet (i.e. plenty of vegetables) helps ensure you're naturally getting the phytonutrient synergism needed.

One of the easiest ways to ensure you're getting enough vegetables in your diet is by juicing them. For more information, please see my juicing page. You can also squeeze some fresh lemon or lime juice into some water for a vitamin C rich beverage.

When taking an oral vitamin C, you also want to be mindful of your dosing frequency. Dr. Steve Hickey, who wrote the book Ascorbate, has shown that if you take vitamin C frequently throughout the day, you can achieve much higher plasma levels.

So even though your kidneys will tend to rapidly excrete the vitamin C, by taking it every hour or two, you can maintain a much higher plasma level than if you just dose it once a day (unless you're taking an extended release form of vitamin C).

Iron Deficiency Can Raise Stroke Risk in Certain Individuals

Recent research also suggests that iron deficiency can increase your risk of ischemic stroke if you have hereditary hemorrhagic telangiectasia, a hereditary disease that causes enlarged blood vessels in your lungs. Iron deficiency increases the stickiness of your blood, which increases your risk of blood clots, and in those with this genetic abnormality, such clots can travel through your lungs and into your brain.

According to the study in question, published in the journal PLOS One,7 even having moderately low iron levels can double your stroke risk if you have this condition. According to the researchers, other health conditions may also permit blood clots to bypass the filtration system of your lungs. Study author Dr. Claire Shovlin stated that:

"The next step is to test whether we can reduce high-risk patients' chances of having a stroke by treating their iron deficiency. We will be able to look at whether their platelets become less sticky. There are many additional steps from a clot blocking a blood vessel to the final stroke developing, so it is still unclear just how important sticky platelets are to the overall process. We would certainly encourage more studies to investigate this link."

Sun Exposure Also Plays Multiple Roles in Stroke Prevention

Another nutrient that is very important for stroke prevention is vitamin D. According to research presented at the American Heart Association's (AHA) Annual Scientific Sessions in 2010,8 low levels of vitamin D—the essential nutrient obtained from sun exposure—doubles the risk of stroke in Caucasians. 

While many opt for vitamin D3 supplements to raise their vitamin D level, I strongly recommend optimizing your levels through appropriate sun exposure or by using a safe tanning bed (i.e. one with electronic ballasts rather than magnetic ballasts, to avoid unnecessary exposure to EMF fields). Ideally, you'll want to maintain your vitamin D level within the range of 50-70 ng/ml year-round.

Vitamin D3 supplements are best used as a last resort, as they will not provide you with any of the other health benefits associated with sun exposure... If you do opt for a supplement, the most recent research suggests the average adult needs to take about 8,000 IUs of vitamin D per day in order to elevate their levels above 40 ng/ml, which is the absolute minimum for disease prevention.

If you opt for a supplement, you also need to make sure you're getting sufficient amounts of vitamin K2, as it works synergistically with vitamin D and activates matrix GLA protein, which inhibits arterial calcification. That said, exposing your skin to sunlight will also suppress your risk of stroke by altering the level of nitric oxide in your skin, which dilates your blood vessels and normalizes your blood pressure.9

Previous research10, 11 has shown that reducing your systolic blood pressure by 20 millimeters (regardless of how high your blood pressure currently is) decreases your risk of stroke by 50 percent. Reduce it by another 20 mm, and you cut your individual risk in half yet again. One way to naturally reduce your blood pressure is through exercise. Another is by making sure you're getting enough sun exposure. According to Martin Feelisch, a professor of experimental medicine at the University of Southampton in southern England:12

"Avoiding excess sunlight exposure is critical to prevent skin cancer, but not being exposed to it at all, out of fear or as a result of a certain lifestyle, could increase the risk of cardiovascular disease."

Interestingly, previous research13 also suggests that inducing nitric oxide (NO) actually helps protect your skin against UV damage... Another crucial element in the normalization of blood pressure is to address insulin and leptin resistance, which is present in about 80 percent of the population from eating far too many carbohydrates and not getting enough exercise. If you have high blood pressure and are overweight, your first step would be to eliminate all grains, sugars, and processed foods, and increase healthy fats, like avocado, coconut oil, butter, and nuts.

Weather Changes Influence Stroke Rates

In related news, yet another recent study claims there's a link between weather conditions and stroke hospitalization rates. The researchers speculate that meteorological factors such as fluctuations in temperature and humidity may act as stressors. As reported by Medical News Today:14

"Lichtman and her team analyzed the medical records of 134,510 patients hospitalized in 2009-10 with ischemic stroke, which is caused by a blood clot blocking the blood flow to the brain. They then cross-referenced this data with meteorological records of temperature and dew point data from this period.

The team found that large daily temperature changes and higher-than-average air moisture were linked to higher hospitalization rates from stroke. Lower-than-average annual temperatures were also associated with death and hospitalization from stroke. [Lichtman says] 'People at risk for stroke may want to avoid being exposed to significant temperature changes and high dew point and, as always, be prepared to act quickly if they or someone they know experiences stroke signs and symptoms.'"

Don't Depend on Your Cholesterol Level to Assess Your Stroke Risk

High cholesterol is an oft-cited risk factor for stroke, but total cholesterol alone will tell you virtually nothing about your disease risk, unless it's exceptionally elevated (above 330 or so, which would be suggestive of familial hypercholesterolemia, and is, in my view, about the only time a cholesterol-lowering drug would be appropriate). It's also well worth noting that cholesterol-lowering drugs known as statins have been found to increase your stroke risk, and previous research also suggests that having too little cholesterol in your blood may increase your risk of stroke.

According to research published in 1999,15, 16 individuals with cholesterol levels above 230 milligrams per deciliter of blood (mg/dL) had an elevated risk of ischemic stroke. For example, a person with a cholesterol level of 280 mg/dL had twice the risk of ischemic stroke as a person with 230 mg/dL. But they also found that as cholesterol dropped, the risk of more lethal hemorrhagic stroke increased significantly instead. A person with a cholesterol level below 180 mg/dL had twice the risk of that type of stroke compared with someone at 230 mg/dL.

So, with regards to cholesterol, what you want is proper balance between your HDL, LDL, and total cholesterol. This is best achieved through a healthy diet, as outlined in my Nutrition Plan, and exercise. Two ratios that are far better indicators of heart disease risk are:

  1. Your HDL/total cholesterol ratio: HDL percentage is a very potent indicator of your heart disease risk. Just divide your HDL level by your total cholesterol. This percentage should ideally be above 24 percent. Below 10 percent, it's a significant indicator of risk for heart disease
  2. Your triglyceride/HDL ratios: This ratio should ideally be below 2

Lifesaving Information: How to Recognize a Stroke

A stroke doesn't advertise its pending arrival, which makes prevention all the more important. That said, getting medical help quickly can mean the difference between life and death or permanent disability, should you or someone you love suffer a stroke. This is an area where conventional medicine excels, so please do NOT delay in getting medical attention.

In the case of ischemic stroke, there are emergency medications that can dissolve a blood clot that is blocking blood flow to your brain. If done quickly enough, emergency medicine can prevent or reverse permanent neurological damage—but you typically need treatment within one hour, which means the faster you recognize the signs, the better the prognosis. The National Stroke Association recommends using the FAST acronym to help remember the warning signs of stroke:17

F = FACE: Ask the person to smile. Does one side of the face droop?

A = ARMS: Ask the person to raise both arms. Does one arm drift downward?

S = SPEECH: Ask the person to repeat a simple phrase. Does their speech sound slurred or strange?

T = TIME: If you observe any of these signs, call 9-1-1 immediately.

Other Stroke-Prevention Guidelines

It's important to realize that the vast majority—up to 80 percent, according to the National Stroke Association—of strokes are preventable, so your lifestyle plays a major role in whether or not you're going to become a statistic here. Besides the specific nutritional factors discussed above, other lifestyle factors that can have a direct impact on your stroke risk include:

  • Exercise will go a long way toward improving your insulin and leptin receptor signaling, thereby normalizing your blood pressure and reducing your stroke risk. I recommend a comprehensive program that includes Peak Fitness exercises along with super slow strength training, Active Isolated Stretching and core work. If you've had a stroke, exercise is also very important, as research shows it can significantly improve both your mental and physical recovery.18
  • Processed meats: Certain preservatives, such as sodium nitrate and nitrite found in smoked and processed meats have been shown to damage your blood vessels, which could increase your risk of stroke. I recommend avoiding all forms of processed meats, opting instead for organic, grass-fed or pastured meats.
  • Diet soda. Research presented at the American Stroke Association's International Stroke Conference in 2011 showed that drinking just one diet soda a day may increase your risk of stroke by 48 percent. Ideally, strive to eliminate all soda from your diet, as just one can of regular soda contains nearly twice my recommended daily allowance for fructose in order to maintain good health and prevent disease.
  • Stress. According to a 2008 study,19 the more stressed you are, the greater 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.
  • My favorite overall tool to manage stress is EFT (Emotional Freedom Technique). Other common stress-reduction tools with a high success rate include prayer, meditation, laughter and yoga, for example. For more tips, see my article "10 Simple Steps to Help De-Stress."

  • Hormone replacement therapy (HRT) and birth control pills. If you're on one of the hormonal birth control methods (whether it's the pill, patch, vaginal ring, or implant), it is important to understand that you are taking synthetic progesterone and synthetic estrogen -- something that is clearly not advantageous if you want to maintain optimal health. These contraceptives contain the same synthetic hormones as those used in hormone replacement therapy (HRT), which has well-documented risks, including an increased risk of blood clots, stroke, heart attack, and breast cancer.
  • Statins. Statin drugs are frequently prescribed to reduce your risk of heart disease and stroke. However, research shows that these cholesterol-lowering drugs actually increase your risk of a second stroke if you've already had one. There are two reasons why this might happen: the drugs may either lower cholesterol too much, to the point that it increases your risk of brain bleeding, or they may affect clotting factors in your blood, increasing the bleeding risk.
  • Chances are greater than 100 to 1 that you do not need a statin drug. Seventy-five percent of your cholesterol is produced by your liver, which is influenced by your insulin levels. Therefore, if you optimize your insulin level, you will automatically optimize your cholesterol. For a refresher on how to do this, please see my recent article, "Statin Nation: The Great Cholesterol Cover-Up."

  • Grounding. Walking barefoot, aka "grounding," has a potent antioxidant effect that helps alleviate inflammation throughout your body. The human body appears to be finely tuned to "work" with the Earth in the sense that there's a constant flow of energy between our bodies and the Earth. When you put your feet on the ground, you absorb large amounts of negative electrons through the soles of your feet.
  • High-sugar diets, smoking, radiofrequencies, and other toxic electromagnetic forces, emotional stress, high cholesterol, and high uric acid levels are examples of factors that make your blood hypercoagulable, meaning it makes it thick and slow-moving, which increases your risk of having a blood clot or stroke.

    Grounding helps thin your blood by improving its zeta potential. This gives each blood cell more negative charge which helps them repel each other to keep your blood thin and less likely to clot. This can significantly reduce your risk of stroke. Research has demonstrated it takes about 80 minutes for the free electrons from the earth to reach your blood stream and transform your blood, so make it a point to regularly walk barefoot on grass or on wet sand for about 1.5-2 hours, if possible.


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