Vitamin C has the strongest and most consistent evidence for lowering blood pressure among all vitamins. A meta-analysis of 29 randomized controlled trials found that vitamin C supplementation reduced systolic blood pressure by about 3.8 mmHg and diastolic by about 1.5 mmHg, with a typical dose of 500 mg per day over eight weeks. That’s a modest but meaningful drop, especially when combined with other lifestyle changes. Several other vitamins also show promise, though the evidence varies widely depending on your individual health and even your genetics.
Vitamin C: The Strongest Evidence
Vitamin C appears to lower blood pressure by improving the function of blood vessel walls and acting as an antioxidant that protects nitric oxide, a molecule your body uses to relax blood vessels. A Johns Hopkins meta-analysis published in the American Journal of Clinical Nutrition pooled data from 29 trials and found an average systolic drop of 3.84 mmHg and a diastolic drop of 1.48 mmHg. Among people who already had high blood pressure, the systolic reduction was even larger: about 4.85 mmHg.
The median dose across these trials was 500 mg per day, which is well above the recommended daily intake of 75 to 90 mg but easy to get from a supplement. Most trials lasted about eight weeks before seeing results. Interestingly, large observational studies looking at vitamin C intake from food alone haven’t found a clear link with lower blood pressure, which suggests that the concentrated doses from supplements may be what drives the effect.
Vitamin D: Helpful If You’re Deficient
Vitamin D’s relationship with blood pressure is more complicated. Overall, pooled analyses of clinical trials show no general blood pressure benefit from vitamin D supplements. However, there’s an important exception: people whose blood levels of vitamin D fall below 30 ng/mL may see improvement with supplementation.
The biological mechanism is well understood. Vitamin D suppresses a hormone system called the renin-angiotensin system, which controls how tightly your blood vessels constrict and how much sodium your kidneys retain. Animal studies from the American Heart Association show that when vitamin D signaling is absent, renin levels rise and blood vessels tighten. In humans, your body can convert vitamin D into its active form directly in blood vessel tissue, where it acts locally to reduce this constriction. The safe upper limit for vitamin D is 50 micrograms (2,000 IU) per day, according to European food safety guidelines, though many clinicians use higher doses under supervision for people with confirmed deficiency.
Vitamin B2: A Genetic-Specific Effect
One of the more surprising findings in blood pressure research involves riboflavin (vitamin B2) and a specific genetic variant. About 10 to 12 percent of the population carries two copies of a variant in the MTHFR gene (called the 677TT genotype), which impairs how the body processes folate. People with this variant tend to have higher blood pressure that responds poorly to standard medications.
A targeted trial published by the American Heart Association gave these individuals just 1.6 mg of riboflavin per day for 16 weeks. The result was a 5.6 mmHg drop in systolic blood pressure compared to placebo. After the intervention, 57 percent of the riboflavin group had reached their blood pressure goal, compared to only 30 percent taking a placebo. This is a small, inexpensive vitamin dose with a meaningful effect, but it only works in people with this particular genetic profile. Genetic testing through your doctor can identify whether you carry the variant.
Folic Acid: Protects Against Stroke, Not Blood Pressure
Folic acid is sometimes mentioned alongside blood pressure because of the large CSPPT trial in China, which enrolled over 20,000 adults with hypertension. That trial found that adding folic acid to a standard blood pressure medication significantly reduced the risk of first stroke. But the blood pressure numbers tell a different story: systolic pressure averaged 139.7 mmHg with folic acid versus 139.8 mmHg without it. The difference was essentially zero.
Folic acid’s stroke prevention benefit likely comes from lowering homocysteine, an amino acid linked to blood vessel damage, rather than from any direct effect on blood pressure. If you have high blood pressure and elevated homocysteine levels, folic acid may still be worth discussing with your doctor, but not because it will lower your readings.
Vitamin E: Uncertain and Potentially Risky
A 2024 network meta-analysis in BMJ Open found that vitamin E was the only vitamin among five studied that significantly reduced systolic blood pressure, with an average drop of about 14 mmHg. That sounds impressive, but there are serious caveats. The trials were small, and the confidence interval was wide, meaning the true effect could be much smaller. More concerning, higher blood levels of a specific form of vitamin E (gamma-tocopherol, the type most common in the American diet through soybean and corn oils) were actually associated with higher blood pressure and greater hypertension prevalence. Research has also found that dietary vitamin E intake above about 40 mg per day may increase the risk of developing high blood pressure. Until more is known, vitamin E is not a reliable or safe strategy for blood pressure management.
Potassium and Magnesium: The Mineral Factor
While not vitamins, two minerals deserve mention because they often appear in the same supplement aisle and have strong evidence behind them. The 2025 AHA/ACC hypertension guidelines specifically highlight potassium, noting that moderate supplementation lowers blood pressure by an average of 6 mmHg systolic and 4 mmHg diastolic. That’s a larger effect than any vitamin.
There’s a catch, though. The relationship between potassium and blood pressure follows a U-shaped curve. The greatest benefit occurs at about 30 mmol per day of supplemental potassium, while doses above 80 mmol per day can actually raise blood pressure, especially in people already taking blood pressure medication. The effect is also stronger in people who consume a lot of sodium, particularly above 4,000 mg per day.
Magnesium supplementation has also been shown in pooled analyses to reduce both systolic and diastolic blood pressure, and higher dietary magnesium intake is associated with a lower risk of developing hypertension in the first place.
Food-Based Approaches vs. Supplements
The DASH diet (Dietary Approaches to Stop Hypertension) remains one of the most effective non-drug strategies for lowering blood pressure, and it works partly by loading your diet with the same nutrients discussed above: potassium, magnesium, vitamin C, and fiber from fruits, vegetables, whole grains, and low-fat dairy. The DASH plan significantly lowers blood pressure in people with both normal and high readings.
For most vitamins, the evidence for blood pressure reduction comes specifically from supplement doses that are higher than what you’d get from food alone. Vitamin C trials used 500 mg per day, roughly the amount in six or seven oranges. The riboflavin dose of 1.6 mg is achievable through diet (a cup of yogurt and a serving of fortified cereal would get you there), but the benefit only applies to people with the MTHFR variant. A food-first approach gives you the broadest combination of nutrients, and supplements can fill specific gaps where higher doses have proven effective.
Supplements That Can Raise Blood Pressure
Some supplements marketed as “natural” can work against your blood pressure goals. The 2025 AHA guidelines specifically warn against herbal supplements containing Ma Huang (ephedra) and certain combinations of St. John’s wort. St. John’s wort doesn’t directly raise blood pressure, but it can change how your body metabolizes cardiovascular medications, making them less effective. Arnica, commonly used for pain and bruising, can also reduce the effectiveness of blood pressure medication. If you’re taking any antihypertensive drugs, check with your pharmacist before adding new supplements to your routine, since interactions are common and not always obvious.