A 2026 cross-sectional analysis of 17,484 American adults found that consuming the highest amounts of B vitamins (thiamin, riboflavin, and niacin) was associated with 16-23% higher odds of high blood pressure compared to lowest intake levels. According to Gram Research analysis, this suggests excessive B vitamin supplementation may increase hypertension risk, though the study cannot prove causation. Riboflavin showed a protective effect against arterial stiffness, indicating these vitamins have complex effects on heart health.
A major study of nearly 17,500 American adults found something surprising: people who consumed the highest amounts of three B vitamins—thiamin, riboflavin, and niacin—had higher rates of high blood pressure. According to Gram Research analysis, this challenges the common belief that more vitamins are always healthier. The research, which looked at data from 1999 to 2023, suggests that excessive B vitamin intake, especially from supplements, may increase hypertension risk. However, scientists caution that this doesn’t prove B vitamins cause high blood pressure—it just shows a connection that needs more investigation.
Key Statistics
A 2026 cross-sectional study of 17,484 U.S. adults found that the highest intake of riboflavin was associated with 23% increased odds of hypertension compared to the lowest intake, even after adjusting for age, weight, and other health factors.
According to research reviewed by Gram analyzing NHANES data from 1999-2023, niacin intake showed a J-shaped relationship with hypertension risk, with the lowest risk observed at 30-40 mg per day, suggesting an optimal intake level exists.
In a 2026 analysis of 17,484 Americans, high riboflavin intake was associated with 16% lower odds of increased pulse pressure (arterial stiffness), indicating this B vitamin may have protective effects on arterial flexibility.
A 2026 cross-sectional study found that thiamin intake in the highest quartile was associated with 17% increased odds of hypertension, suggesting excessive supplementation may increase blood pressure risk.
The Quick Take
- What they studied: Whether eating or taking high amounts of three B vitamins (thiamin, riboflavin, and niacin) is connected to high blood pressure and stiff arteries in American adults.
- Who participated: 17,484 U.S. adults aged 20 and older who participated in national health surveys between 1999 and 2023. The group included people of different ages, races, and income levels.
- Key finding: Adults who consumed the highest amounts of these three B vitamins were 16-23% more likely to have high blood pressure compared to those who consumed the least. Interestingly, riboflavin showed a protective effect against arterial stiffness.
- What it means for you: If you’re taking B vitamin supplements, this research suggests you shouldn’t exceed recommended daily amounts without talking to your doctor. Getting B vitamins from food appears safer than high-dose supplements. However, this study shows association, not cause-and-effect, so more research is needed before changing your routine.
The Research Details
Researchers analyzed health data collected from thousands of Americans over 24 years through the National Health and Nutrition Examination Survey (NHANES). This is a cross-sectional study, meaning they took a snapshot of people’s vitamin intake and blood pressure at one point in time, rather than following them over years.
Participants reported everything they ate and any supplements they took. Researchers then divided people into four groups based on how much thiamin, riboflavin, and niacin they consumed (from both food and supplements combined). They measured blood pressure and calculated something called “pulse pressure”—the difference between the top and bottom blood pressure numbers, which indicates how stiff your arteries are.
The team used statistical models to account for other factors that affect blood pressure, like age, weight, exercise, salt intake, and existing health conditions. They also looked for nonlinear relationships, meaning they checked whether the risk increased smoothly or had a sweet spot where risk was lowest.
This approach is important because it uses real-world data from a nationally representative sample of Americans, making the findings more applicable to the general population than small laboratory studies. By adjusting for many other factors, researchers could isolate the vitamin effect more clearly. However, the cross-sectional design means we can only see associations, not prove that vitamins cause high blood pressure.
Strengths: Large sample size (17,484 people), long time period (24 years of data), detailed dietary information, and adjustment for many confounding factors. Weaknesses: Cross-sectional design cannot prove causation, relies on people’s memory of what they ate, cannot rule out unmeasured confounding factors, and the sample size reported (484) appears to be a data entry error given the abstract states 17,484 participants.
What the Results Show
The study found that people consuming the highest amounts of thiamin had a 17% increased odds of high blood pressure, riboflavin had a 23% increased odds, and niacin had a 16% increased odds, all compared to the lowest intake groups. These associations remained even after accounting for age, weight, exercise, diet quality, and other health factors.
For pulse pressure (arterial stiffness), only riboflavin showed a protective effect—high intake was associated with 16% lower odds of having stiff arteries. Thiamin and niacin showed no clear relationship with pulse pressure.
When researchers looked more carefully at niacin, they found a J-shaped curve, meaning risk was lowest at moderate intakes (30-40 mg per day) and increased at both lower and higher amounts. This suggests there may be an optimal intake level for niacin, though the pattern wasn’t as clear for the other two vitamins.
Subgroup analyses examining different age groups, sexes, and racial/ethnic groups showed largely consistent associations, suggesting the findings apply broadly across the U.S. population. The protective effect of riboflavin on pulse pressure was particularly interesting and unexpected, suggesting this vitamin may have different effects on different aspects of heart health.
Previous research has generally shown that B vitamins are important for heart health and that deficiencies increase disease risk. This study adds a cautionary note: excessive intake, particularly from supplements, may have unintended consequences. The findings align with emerging research suggesting that more of a nutrient isn’t always better and that balance is important.
This study cannot prove that B vitamins cause high blood pressure—it only shows an association. People with high blood pressure might take more supplements, creating reverse causation. The study relies on people remembering what they ate, which can be inaccurate. Other unmeasured factors (like stress, sleep, or genetic factors) could explain the relationship. The cross-sectional design is a snapshot in time, not a long-term follow-up.
The Bottom Line
Moderate confidence: Get B vitamins from food sources (whole grains, meat, eggs, legumes) rather than high-dose supplements. Follow recommended daily amounts: thiamin 1.1-1.2 mg, riboflavin 1.1-1.3 mg, and niacin 14-16 mg for adults. If you take supplements, discuss your intake with your doctor, especially if you have high blood pressure or heart disease risk factors.
People with high blood pressure or at risk for it should pay attention to this research. Those taking B vitamin supplements should review their intake with a healthcare provider. People with B vitamin deficiencies should still take supplements as recommended by their doctor. Healthy people eating a balanced diet likely get adequate B vitamins without supplementation.
Blood pressure changes from dietary modifications typically take 2-4 weeks to show measurable effects. If you reduce supplement intake, you may see improvements in blood pressure readings within 4-8 weeks, though individual responses vary.
Frequently Asked Questions
Can too many B vitamins cause high blood pressure?
This 2026 study of 17,484 adults found associations between high B vitamin intake and increased hypertension risk, but cannot prove causation. The connection suggests excessive supplementation may be problematic, though more research is needed to confirm whether B vitamins directly cause high blood pressure.
Should I stop taking B vitamin supplements if I have high blood pressure?
Don’t stop without consulting your doctor. This study suggests avoiding excessive amounts beyond recommended daily values. Talk with your healthcare provider about your specific supplement intake and whether reducing doses or switching to food sources might help manage your blood pressure.
What’s the safe amount of B vitamins to take daily?
Recommended daily amounts are thiamin 1.1-1.2 mg, riboflavin 1.1-1.3 mg, and niacin 14-16 mg for adults. Most people get adequate amounts from food. This study suggests avoiding high-dose supplements beyond these recommendations, particularly if you have hypertension risk factors.
Are B vitamins from food safer than supplements?
This study examined total intake from both sources but suggests excessive supplementation may be problematic. Getting B vitamins from whole grains, meat, eggs, and legumes provides balanced amounts without overdosing, making food sources a safer approach for most people.
Which B vitamin is most concerning for blood pressure?
All three B vitamins studied (thiamin, riboflavin, niacin) showed associations with higher hypertension risk at highest intake levels. Riboflavin showed the strongest association (23% increased odds), though the study cannot determine which is most problematic or whether the effect is causal.
Want to Apply This Research?
- Log daily B vitamin intake from both food and supplements (in mg), and track systolic/diastolic blood pressure readings weekly. Create a correlation view showing whether reducing supplement intake correlates with lower blood pressure readings over 8-12 weeks.
- Set a daily reminder to review supplement bottles and calculate total B vitamin intake. Create a goal to meet recommended daily amounts without exceeding them. Replace high-dose supplements with food sources when possible (e.g., whole wheat bread for thiamin, eggs for riboflavin, chicken for niacin).
- Track blood pressure trends monthly and correlate with B vitamin intake changes. Monitor for symptoms of excessive supplementation (nausea, tingling). Schedule quarterly check-ins with healthcare provider to review supplement regimen and blood pressure control.
This research shows associations between B vitamin intake and blood pressure but cannot prove cause-and-effect relationships. Do not stop taking prescribed medications or recommended supplements without consulting your healthcare provider. If you have high blood pressure or heart disease, discuss your supplement intake with your doctor before making changes. This study applies to general populations and may not apply to individuals with specific medical conditions or B vitamin deficiencies. Always consult a healthcare professional before significantly changing your supplement regimen.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.