Researchers combined results from 9 major studies involving nearly 24,000 people to see if taking folic acid and B vitamins could help people with kidney disease. They found that these vitamins might provide a very small benefit in slowing kidney disease, but the improvement was so small it may not make a real difference in people’s lives. The vitamins didn’t help prevent heart problems or extend lifespan. The study suggests these vitamins might work better for people with milder kidney disease and for certain ethnic groups, but more research is needed before doctors can recommend them as a standard treatment.

The Quick Take

  • What they studied: Whether taking folic acid and B vitamins can slow down kidney disease and prevent related health problems like heart disease and death
  • Who participated: Nearly 24,000 people across 9 different research studies who had kidney disease at various stages, from mild to severe
  • Key finding: B vitamins showed only a tiny reduction in kidney disease progression (4% improvement), which is so small it may not matter in real life. They had no effect on heart disease or death rates.
  • What it means for you: If you have kidney disease, taking B vitamins probably won’t significantly change your disease progression. Talk to your doctor before starting any new supplements, as they may not be right for everyone with kidney problems.

The Research Details

This was a meta-analysis, which means researchers looked at 9 high-quality studies that had already been completed and combined all their results together. Each of these 9 studies was a randomized controlled trial, which is the gold standard in medical research—some people got B vitamins (folic acid alone or combined with other B vitamins) while others got a placebo (fake pill) or continued their regular care. By combining all these studies, the researchers could see the bigger picture of whether B vitamins really help kidney disease patients.

The researchers carefully searched medical databases through January 2025 to find all relevant studies. They looked at what happened to patients over time, tracking whether their kidney disease got worse, if they had heart problems, or if they died. This approach is powerful because it combines information from thousands of people rather than just one study.

This research approach matters because kidney disease is very common and serious, and doctors are always looking for affordable, safe treatments. High blood levels of a substance called homocysteine (which B vitamins can lower) are linked to kidney disease getting worse. By combining multiple studies, researchers can see if this connection actually means B vitamins help—or if it’s just a coincidence. The large number of participants (almost 24,000 people) makes the results more reliable than any single study could be.

This study is reliable because it followed strict international guidelines for combining research studies. The researchers looked at 9 randomized controlled trials, which are the highest-quality type of study. The results were consistent across studies (low variation between them), meaning the findings are stable. However, the benefit found was very small, which raises questions about whether it’s meaningful in real life. The study also showed that benefits might differ depending on a person’s race/ethnicity and how advanced their kidney disease is.

What the Results Show

When researchers combined all 9 studies, they found that B vitamins reduced the risk of kidney disease getting worse by only 4% compared to placebo or regular care. While this was statistically significant (meaning it probably wasn’t due to chance), the improvement was so tiny that doctors question whether patients would actually notice or benefit from it in their daily lives.

When researchers looked at specific groups, they found more promising results in two populations: people with normal to moderate kidney disease (not the most severe cases) showed about an 11% reduction in disease progression, and non-White populations showed similar benefits. This suggests B vitamins might work better for some people than others, though researchers aren’t sure why.

The vitamins had no measurable effect on preventing heart attacks or strokes (6% reduction that wasn’t statistically significant) and didn’t help people live longer (1% reduction in death rate, essentially no effect). These were important outcomes because people with kidney disease often die from heart problems, so if B vitamins could prevent those, it would be very valuable.

The research showed that the benefit of B vitamins was consistent across different studies, which is good news for reliability. However, the consistency of the small benefit also suggests this isn’t a breakthrough treatment. The fact that certain groups (people with milder kidney disease and some ethnic groups) showed better results suggests that B vitamins might work through different mechanisms in different people, or that some people’s bodies respond better to the treatment than others.

This finding aligns with previous research suggesting that simply lowering homocysteine levels doesn’t automatically improve kidney disease outcomes. Earlier studies had shown that high homocysteine is associated with worse kidney disease, leading doctors to hope that lowering it would help. However, this meta-analysis confirms what some recent research has suggested: lowering a risk factor doesn’t always translate to better health outcomes. This is a common lesson in medicine—just because something is abnormal doesn’t mean fixing it will help.

The main limitation is that the benefit found was so small it may not be clinically meaningful. The studies included varied in how they measured outcomes and how long they followed patients. Some studies were older and used different methods than modern research. The research couldn’t fully explain why some groups (non-White populations, people with milder disease) seemed to benefit more, so these findings need confirmation. Additionally, most participants were from developed countries, so results may not apply equally worldwide. The studies didn’t look at potential harms from long-term B vitamin use, which is important since some people take these supplements for years.

The Bottom Line

Based on this research, B vitamins cannot be recommended as a standard treatment to slow kidney disease progression. The benefit is too small to justify routine use. However, if you have kidney disease and your doctor has identified high homocysteine levels, a discussion about B vitamins might be worthwhile, especially if you have milder kidney disease. Always consult your nephrologist (kidney specialist) before starting any supplements, as some B vitamins can accumulate in people with severe kidney disease. Confidence level: Moderate—this is based on a large number of studies, but the effect is very small.

People with chronic kidney disease should know about this research, especially those considering B vitamin supplements. Healthcare providers treating kidney disease patients should be aware that B vitamins don’t provide the significant benefit once hoped for. People with normal kidney function don’t need to worry about this research. Those with very advanced kidney disease should be especially cautious about supplements without doctor approval. Interestingly, people from non-White backgrounds with kidney disease might want to discuss B vitamins with their doctors, as this study suggested they might benefit more.

If B vitamins were to help, benefits would likely appear over months to years, not weeks. The studies in this analysis followed people for varying lengths of time, but most tracked outcomes for at least 6 months to several years. Don’t expect immediate changes if you start taking B vitamins—kidney disease progression is slow, and any benefits would be gradual.

Want to Apply This Research?

  • Track kidney function markers (GFR or creatinine levels from doctor visits) every 3 months if you have kidney disease, noting whether you’re taking B vitamins. This helps you and your doctor see if your kidney disease is stable, improving, or worsening—the real measure of whether any treatment is working.
  • If your doctor approves B vitamins, set a daily reminder to take them at the same time each day (like with breakfast). Use the app to log when you take them and note any side effects. This helps you stay consistent and gives your doctor information about adherence if you discuss whether the treatment is working.
  • Create a long-term tracking dashboard showing your kidney function test results over time alongside your B vitamin use. Include notes about diet changes, other medications, and how you’re feeling. Share this with your nephrologist at each visit to have an informed discussion about whether the vitamins are helping or if other approaches might be better.

This research summary is for educational purposes only and should not replace professional medical advice. B vitamins can interact with medications and may not be appropriate for all people with kidney disease, particularly those with advanced disease. Some B vitamins can accumulate to harmful levels in people with severe kidney problems. Before starting any B vitamin supplement, consult with your nephrologist or primary care doctor, especially if you have kidney disease, take other medications, or have other health conditions. This study shows B vitamins provide minimal benefit for kidney disease progression and no benefit for heart disease or survival, so discuss realistic expectations with your healthcare provider.