Researchers studied 120 people with ALS (a disease affecting nerve cells) to see if vitamin B12 supplements could help. They found that taking B12 supplements did increase the amount of B12 in patients’ blood and lowered a harmful substance called homocysteine. Interestingly, patients who took B12 supplements showed slower disease progression in the first few months compared to later months. However, the supplements didn’t appear to extend how long people lived. While these results are promising for slowing early disease progression, more research is needed to confirm these findings and understand why B12 helps initially but not long-term survival.

The Quick Take

  • What they studied: Whether taking vitamin B12 and folate supplements could slow down ALS (a disease that weakens muscles) and help people live longer
  • Who participated: 120 people in China who had been diagnosed with ALS. All of them were offered B12 and folate supplements and had their blood tested to measure vitamin levels
  • Key finding: Taking B12 supplements increased B12 levels in the blood and lowered a harmful substance called homocysteine. In the first 3-6 months, people taking supplements showed slower disease progression compared to months 9-12, but supplements didn’t affect how long people lived
  • What it means for you: If you have ALS, B12 supplements may help slow down disease progression in the early stages, which could be valuable time. However, this doesn’t appear to extend survival time, and more research is needed before making it a standard treatment recommendation

The Research Details

This was an observational study where researchers followed ALS patients over time and tracked what happened when they took B12 and folate supplements. All 120 patients were offered the supplements, and researchers measured their blood levels of B12, folate, and a substance called homocysteine before and after taking the supplements. They then watched how quickly the disease progressed and how long patients survived.

The researchers compared patients who took the supplements to those who didn’t, and also looked at whether having higher or lower vitamin levels in the blood made a difference. They measured disease progression by tracking how quickly patients’ symptoms got worse over different time periods (first 3-6 months versus 9-12 months).

This type of study is useful for spotting patterns and connections, but it can’t prove that supplements directly cause improvements because patients weren’t randomly assigned to take them or not—they chose whether to take them.

Understanding whether simple, affordable supplements like B12 could help ALS patients is important because ALS is a serious disease with limited treatment options. If supplements could even slow progression in early stages, it might give patients more time with better function. This research helps doctors decide what to recommend and guides future studies on more expensive or complex treatments.

This study followed real patients over time, which is good for understanding real-world effects. However, the study size of 120 patients is relatively small, and it wasn’t a randomized controlled trial (where patients are randomly assigned to take supplements or not), so we can’t be completely certain the supplements caused the improvements. The fact that disease progression slowed in early months but not later suggests the relationship is complex and needs more investigation.

What the Results Show

When ALS patients took B12 supplements, their blood levels of B12 increased significantly, and their folate levels also went up. At the same time, their levels of homocysteine (a substance that can be harmful to nerve cells) decreased. These changes in blood chemistry happened reliably when patients took the supplements.

The most interesting finding was about disease progression timing. In the first 3-6 months after starting supplements, patients showed slower disease progression compared to what they experienced in months 9-12. This suggests the supplements might have an early protective effect. However, this benefit appeared to wear off or become less noticeable over time.

Surprisingly, despite these positive changes in blood chemistry and early slowing of progression, taking B12 supplements did not affect how long patients lived overall. Patients who took supplements lived about the same length of time as those who didn’t take them.

The study also looked at whether having naturally high or low levels of B12, folate, or homocysteine in the blood (before taking supplements) made a difference in survival. It didn’t—patients with high or low levels of these substances had similar survival times. This suggests that the absolute level of these vitamins in the blood may be less important than the changes that happen when supplements are taken.

Previous research has suggested that high homocysteine levels might be harmful in ALS, so lowering it seemed promising. This study confirms that B12 supplements can lower homocysteine, which is good. However, the finding that this doesn’t extend survival is somewhat surprising and suggests that lowering homocysteine alone may not be enough to change the overall course of the disease. The early slowing of progression is a new finding that hasn’t been clearly documented before.

The main limitation is that this wasn’t a randomized controlled trial, so we can’t be completely sure the supplements caused the improvements rather than other factors. Patients who chose to take supplements might have been different in other ways from those who didn’t. The study only included 120 patients, which is a relatively small number for drawing firm conclusions. Additionally, the study was conducted in China with a specific population, so results might not apply equally to other groups. The fact that benefits appeared early but not late in the disease suggests the relationship is complicated and needs more study to understand why.

The Bottom Line

For ALS patients: B12 and folate supplements appear safe and may help slow disease progression in the early stages (first 3-6 months). Taking these supplements is reasonable to discuss with your doctor, especially early in diagnosis. However, don’t expect them to extend survival time based on current evidence. Confidence level: Moderate—the findings are promising but need confirmation in larger studies.

This research is most relevant to people recently diagnosed with ALS and their doctors. It’s less relevant to people in later stages of ALS since the benefits appeared to fade over time. People with other neurological conditions should not assume these results apply to them without consulting their doctor. This is not a substitute for standard ALS treatments.

If B12 supplements are going to help, the benefit appears most likely in the first 3-6 months after starting them. After that, the protective effect seems to decrease. You should discuss with your doctor how long to continue supplements if you’re not seeing benefits.

Want to Apply This Research?

  • Track weekly symptom progression using a simple 1-10 scale for muscle weakness in your legs, arms, and speech. Record this in the first 3 months of starting B12 supplements, then continue monthly. Compare your progression rate before and after starting supplements to see if there’s a noticeable difference.
  • Set a daily reminder to take B12 and folate supplements at the same time each day. Log each dose in your health app. Also track any side effects or changes you notice. Share this log with your doctor at each visit to help them assess whether the supplements are helping your specific situation.
  • Create a simple chart showing your symptom progression over 12 months. Mark when you started supplements. Look for any slowdown in progression in months 1-6 compared to months 7-12. Share this visual record with your healthcare team to help guide decisions about continuing supplements and inform discussions about other treatment options.

This research is informational only and should not replace professional medical advice. ALS is a serious condition requiring care from qualified neurologists. Before starting any supplements, including B12 and folate, consult with your doctor, especially if you’re taking other medications. While this study suggests B12 supplements may slow early disease progression, they are not a cure and should be considered as part of a comprehensive treatment plan, not as a standalone treatment. Individual results may vary, and what works for one person may not work for another.