Scientists studied whether taking folic acid and vitamin B12 supplements could help women with lupus by changing how their genes work in fat tissue. They gave 50 women either the supplements or a placebo for 12 weeks. The results were surprising: the supplements changed gene activity in normal-weight women but had no effect on overweight women. This suggests that extra body weight might block the benefits of these vitamins, and doctors may need different approaches for different patients with lupus.

The Quick Take

  • What they studied: Whether taking folic acid and vitamin B12 supplements could change how genes work in fat tissue of women with lupus, and whether body weight affects this process
  • Who participated: 50 women with lupus who weren’t currently experiencing active symptoms. Half were normal weight (23 women) and half were overweight (27 women). All were premenopausal.
  • Key finding: In normal-weight women, the supplements changed 120 different genes in fat tissue related to immune function and inflammation. In overweight women, the supplements made no detectable changes to genes.
  • What it means for you: If you have lupus and are considering B vitamin supplements, your body weight may affect whether they work for you. This suggests a ‘one-size-fits-all’ approach to lupus treatment may not be best, and personalized nutrition plans might be more effective.

The Research Details

This was a randomized controlled trial, which is considered one of the strongest types of medical research. Researchers randomly assigned 50 women with lupus to receive either daily supplements (400 micrograms of folic acid and 2000 micrograms of vitamin B12) or a placebo (fake pill) for 12 weeks. Neither the participants nor the researchers knew who got the real supplements—this is called ‘double-blind’ and helps prevent bias. Before and after the 12 weeks, researchers examined fat tissue samples to look at which genes were turned on or off using advanced technology called the Illumina EPIC BeadChip platform, which can detect tiny changes in genetic activity.

The researchers divided participants into two groups based on body weight: normal weight and excess body weight. This allowed them to see if body weight affected how the supplements worked. They measured vitamin levels in the blood and looked at many different genetic markers to understand what changed.

This study design is important because it helps prove cause-and-effect relationships. By randomly assigning people to groups and using a placebo, researchers can be more confident that any changes they see are actually from the supplements, not from other factors. Looking at fat tissue specifically matters because fat tissue plays a big role in inflammation and immune system problems in lupus patients.

This study has several strengths: it’s a randomized controlled trial (the gold standard), it’s double-blind (reducing bias), and it uses advanced genetic testing technology. However, the sample size is relatively small (50 people), which means results might not apply to everyone. The study only included women with inactive lupus, so results might differ for men or people with active disease. The study was completed recently and published in a peer-reviewed journal, which adds credibility.

What the Results Show

The supplements successfully increased blood levels of folic acid and vitamin B12 in both groups, confirming that people actually absorbed the vitamins. However, the effects on genes were very different depending on body weight.

In normal-weight women, the supplements caused changes in 120 different genetic locations. Of these, 74 became more active and 46 became less active. These genes were related to immune function, inflammation, obesity, and metabolic health—all important for lupus.

In overweight women, there were no detectable changes in any genes. This was the most surprising finding. The researchers suggest this might be because obesity causes chronic inflammation that interferes with how the body uses these vitamins, or because excess fat tissue changes how folic acid is processed in the body.

The study found that normal-weight women had a greater increase in blood vitamin levels compared to overweight women, even though both groups took the same dose. This suggests that body weight may affect how the body absorbs and uses these vitamins. The genes that changed in normal-weight women were involved in pathways that control immune responses and inflammation—exactly the systems that go wrong in lupus.

Previous research has shown that folic acid and vitamin B12 can affect how genes work in other conditions, but this is one of the first studies to look specifically at lupus patients and to examine how body weight affects this process. Most earlier studies didn’t separate results by body weight, which may explain why some studies showed benefits while others didn’t.

The study only included 50 women, which is a relatively small number. Results might be different in men or in people with active lupus symptoms. The study only lasted 12 weeks, so we don’t know if benefits would continue longer or if problems might develop. All participants were premenopausal women, so results might not apply to postmenopausal women or men. The study didn’t measure whether these genetic changes actually improved lupus symptoms or disease activity.

The Bottom Line

If you have lupus and are normal weight, B vitamin supplementation may be worth discussing with your doctor, as it appears to activate genes involved in immune health. If you have lupus and are overweight, these supplements may not work the same way, and weight management might be a better first step. These findings suggest that personalized nutrition plans based on body weight may be more effective than standard recommendations. Confidence level: Moderate—this is promising research but needs confirmation in larger studies.

Women with lupus should pay attention to these findings, especially those considering B vitamin supplements. Healthcare providers treating lupus patients should consider body weight when recommending supplements. People interested in precision medicine (tailoring treatments to individual characteristics) will find this research relevant. This research is less relevant for people without lupus or for men, though similar patterns might exist.

The study lasted 12 weeks, which is when genetic changes were detected. It’s unclear how long benefits would last or how quickly symptoms might improve. Most people wouldn’t notice genetic changes directly—benefits would likely appear as improvements in inflammation markers or lupus symptoms over weeks to months.

Want to Apply This Research?

  • Track daily B vitamin intake (folic acid and B12 dosage), body weight weekly, and lupus symptom severity (fatigue, joint pain, rashes) on a scale of 1-10 daily. Note any changes in inflammation markers if you have recent blood work.
  • If normal weight with lupus, consider adding a daily B vitamin supplement (after consulting your doctor) and log it in the app. Set reminders for consistent daily intake. If overweight, focus on tracking weight loss progress alongside any supplement use, as the research suggests weight management may be key to supplement effectiveness.
  • Over 12 weeks, track whether symptoms improve, energy increases, or inflammation markers decrease. Compare results between weeks 1-4, 5-8, and 9-12. If overweight, prioritize weight loss tracking and reassess supplement effectiveness after reaching a healthier weight range. Share tracked data with your healthcare provider to personalize your lupus management plan.

This research is preliminary and should not replace medical advice from your doctor. The study was small and only included women with inactive lupus, so results may not apply to everyone. If you have lupus or are considering B vitamin supplements, consult your healthcare provider before starting any new supplement regimen, especially if you take other medications. Lupus is a serious condition requiring professional medical management. This article explains research findings but is not medical advice.