Reviewed By
Reviewed By
Overview
SCIENTIFIC SCORE
Possibly Effective
Based on 15 Researches
7.6
USERS' SCORE
Good
Based on 23 Reviews
8.7
Supplement Facts
Serving Size: 1 Tablet
Amount Per Serving
%DV
Vitamin B₁₂ (as Methylcobalamin)
1,000 mcg
41,667%
Top Medical Research Studies
9
We examined a case of a 51-year-old Ugandan man who experienced recurring lower limb weakness linked to pernicious anemia, an autoimmune condition causing vitamin B12 deficiency. After initial treatments, his symptoms reappeared, leading to further testing that confirmed the diagnosis.
Treatment with vitamin B12 injections significantly improved his condition. This case emphasizes the need for healthcare providers to recognize the signs of vitamin B12 deficiency early, particularly in resource-limited settings, to ensure timely diagnosis and treatment.
Treatment with vitamin B12 injections significantly improved his condition. This case emphasizes the need for healthcare providers to recognize the signs of vitamin B12 deficiency early, particularly in resource-limited settings, to ensure timely diagnosis and treatment.
Read More
9
We explored the intriguing case of a 56-year-old man diagnosed with Biermer's disease, also known as pernicious anemia, an autoimmune condition that leads to a lack of intrinsic factor and, consequently, vitamin B12 malabsorption. This patient presented with unusual symptoms: not just digestive concerns like melena, but also notable neurological effects such as memory issues and gait disturbances.
During our examination, we discovered symptoms indicative of cerebellar ataxia, along with a red and swollen limb that pointed toward deep vein thrombosis (DVT). The tests revealed severe macrocytic anemia and confirmed a deficiency in vitamin B12 while keeping folate levels normal. Following a thorough diagnosis—including gastroscopy, ultrasound, and blood tests—we initiated a treatment plan that included vitamin B12 supplementation and anticoagulant therapy.
The outcome of our intervention was promising, with significant clinical improvement observed in the patient’s condition. Our findings reinforce the essential role of vitamin B12 in managing this type of autoimmune disorder, particularly when neurological and cardiovascular complications arise.
During our examination, we discovered symptoms indicative of cerebellar ataxia, along with a red and swollen limb that pointed toward deep vein thrombosis (DVT). The tests revealed severe macrocytic anemia and confirmed a deficiency in vitamin B12 while keeping folate levels normal. Following a thorough diagnosis—including gastroscopy, ultrasound, and blood tests—we initiated a treatment plan that included vitamin B12 supplementation and anticoagulant therapy.
The outcome of our intervention was promising, with significant clinical improvement observed in the patient’s condition. Our findings reinforce the essential role of vitamin B12 in managing this type of autoimmune disorder, particularly when neurological and cardiovascular complications arise.
Read More
8
We investigated the potential of vitamin B12 as a treatment for rheumatoid arthritis, particularly focusing on its ability to target an enzyme called peptidylarginine deiminase isoform 4 (PADI-4). PADI-4 plays a crucial role in a process called citrullination, which is often disrupted in autoimmune conditions like rheumatoid arthritis.
Our findings revealed that vitamin B12 effectively inhibits PADI-4, showing a preference for this enzyme over another similar one, PADI-2. This inhibition corresponds to a decrease in overall cellular citrullination, including the citrullination of histone H3, which is also mediated by PADI-4.
Additionally, we observed that hydroxocobalamin, a special form of vitamin B12, significantly reduced the severity of collagen type II antibody-induced arthritis in mice. It also lowered the expression of key inflammatory factors and cytokines associated with rheumatoid arthritis, such as IL-17A, TNFα, and IL-6.
These promising results suggest that vitamin B12 might be an effective therapeutic avenue for managing rheumatoid arthritis, warranting further investigation in future studies.
Our findings revealed that vitamin B12 effectively inhibits PADI-4, showing a preference for this enzyme over another similar one, PADI-2. This inhibition corresponds to a decrease in overall cellular citrullination, including the citrullination of histone H3, which is also mediated by PADI-4.
Additionally, we observed that hydroxocobalamin, a special form of vitamin B12, significantly reduced the severity of collagen type II antibody-induced arthritis in mice. It also lowered the expression of key inflammatory factors and cytokines associated with rheumatoid arthritis, such as IL-17A, TNFα, and IL-6.
These promising results suggest that vitamin B12 might be an effective therapeutic avenue for managing rheumatoid arthritis, warranting further investigation in future studies.
Read More
Most Useful Reviews
9
Improved B12 levels
108 people found this helpful
The best B12 I have ever tried! I had a severe B12 deficiency for many years, and no prescription medication worked. I shifted to methylcobalamin, achieving stable levels of 700-800 nmol/L. I recommend a good B complex alongside B12 supplementation to avoid masking other deficiencies. Methylcobalamin has helped me significantly, and my bloodwork reflects the improvement.
Read More
9
Lowered homocysteine levels
72 people found this helpful
Vitamin B12 effectively reduces homocysteine levels, critical for cardiovascular health. My husband’s levels decreased from 12 μmol/L to 8 μmol/L after taking this supplement, showing improved digestibility compared to cyanocobalamin in multivitamins. We will continue using it, especially as we age.
Read More
9
Better sleep quality
27 people found this helpful
I had no effect on sleep disorders with cyanocobalamin, but methylcobalamin worked wonders. Since I started taking it, I have experienced proper sleep and feel more refreshed in the mornings. It suits me well.
Read More
Medical Researches
SCIENTIFIC SCORE
Possibly Effective
Based on 15 Researches
7.6
- All Researches
9.5
Vitamin B12 supplementation benefits autoimmune patients
We explored the impact of vitamin B12 on patients with autoimmune disorders, particularly those experiencing symptoms often attributed to their underlying conditions. The study presented three cases of individuals with neuropathic pain, depression, fatigue, and muscle weakness, who had their symptoms initially misattributed to rheumatic diseases.
Upon starting vitamin B12 supplementation, these patients showed nearly complete resolution of their symptoms, highlighting the potential benefits of this vitamin in treating related health issues. Interestingly, several participants did not display obvious deficiencies in vitamin B12 levels according to lab tests, suggesting that even those who appear to have sufficient levels could still benefit from supplementation.
Furthermore, we delved into research indicating the nerve-protective properties of vitamin B12, which could play a crucial role in managing pain and neuropathy associated with long-standing rheumatic diseases. Therefore, we recommend that healthcare providers consider checking vitamin B12 levels early in the diagnostic journey for autoimmune conditions, and think about offering supplementation regardless of laboratory findings.
Upon starting vitamin B12 supplementation, these patients showed nearly complete resolution of their symptoms, highlighting the potential benefits of this vitamin in treating related health issues. Interestingly, several participants did not display obvious deficiencies in vitamin B12 levels according to lab tests, suggesting that even those who appear to have sufficient levels could still benefit from supplementation.
Furthermore, we delved into research indicating the nerve-protective properties of vitamin B12, which could play a crucial role in managing pain and neuropathy associated with long-standing rheumatic diseases. Therefore, we recommend that healthcare providers consider checking vitamin B12 levels early in the diagnostic journey for autoimmune conditions, and think about offering supplementation regardless of laboratory findings.
Read More
9
We examined a case of a 51-year-old Ugandan man who experienced recurring lower limb weakness linked to pernicious anemia, an autoimmune condition causing vitamin B12 deficiency. After initial treatments, his symptoms reappeared, leading to further testing that confirmed the diagnosis.
Treatment with vitamin B12 injections significantly improved his condition. This case emphasizes the need for healthcare providers to recognize the signs of vitamin B12 deficiency early, particularly in resource-limited settings, to ensure timely diagnosis and treatment.
Treatment with vitamin B12 injections significantly improved his condition. This case emphasizes the need for healthcare providers to recognize the signs of vitamin B12 deficiency early, particularly in resource-limited settings, to ensure timely diagnosis and treatment.
Read More
9
We examined a fascinating case of a 54-year-old man experiencing the rare overlap of Guillain-Barré Syndrome (GBS) and autoimmune gastritis. After a thorough medical evaluation, which included MRI and biopsy, he was diagnosed with both GBS and a vitamin B12 deficiency linked to atrophic gastritis.
Treatment with intravenous immunoglobulin and methylcobalamin (vitamin B12) led to substantial improvement in his symptoms. This case highlights the importance of recognizing potential nutrient deficiencies, especially those impacting autoimmune disorders like GBS and autoimmune gastritis.
Treatment with intravenous immunoglobulin and methylcobalamin (vitamin B12) led to substantial improvement in his symptoms. This case highlights the importance of recognizing potential nutrient deficiencies, especially those impacting autoimmune disorders like GBS and autoimmune gastritis.
Read More
9
We explored the intriguing case of a 56-year-old man diagnosed with Biermer's disease, also known as pernicious anemia, an autoimmune condition that leads to a lack of intrinsic factor and, consequently, vitamin B12 malabsorption. This patient presented with unusual symptoms: not just digestive concerns like melena, but also notable neurological effects such as memory issues and gait disturbances.
During our examination, we discovered symptoms indicative of cerebellar ataxia, along with a red and swollen limb that pointed toward deep vein thrombosis (DVT). The tests revealed severe macrocytic anemia and confirmed a deficiency in vitamin B12 while keeping folate levels normal. Following a thorough diagnosis—including gastroscopy, ultrasound, and blood tests—we initiated a treatment plan that included vitamin B12 supplementation and anticoagulant therapy.
The outcome of our intervention was promising, with significant clinical improvement observed in the patient’s condition. Our findings reinforce the essential role of vitamin B12 in managing this type of autoimmune disorder, particularly when neurological and cardiovascular complications arise.
During our examination, we discovered symptoms indicative of cerebellar ataxia, along with a red and swollen limb that pointed toward deep vein thrombosis (DVT). The tests revealed severe macrocytic anemia and confirmed a deficiency in vitamin B12 while keeping folate levels normal. Following a thorough diagnosis—including gastroscopy, ultrasound, and blood tests—we initiated a treatment plan that included vitamin B12 supplementation and anticoagulant therapy.
The outcome of our intervention was promising, with significant clinical improvement observed in the patient’s condition. Our findings reinforce the essential role of vitamin B12 in managing this type of autoimmune disorder, particularly when neurological and cardiovascular complications arise.
Read More
8
Vitamin B predicts GBS prognosis
We examined the levels of vitamin B and creatine kinase (CK-NAC) in 50 patients with Guillain-Barré Syndrome (GBS). Through clinical assessments, we compared the patients' functional abilities and found that a deficiency in vitamin B was linked to greater disease severity and respiratory complications.
However, while vitamin B levels seemed to offer insight into GBS prognosis, elevated CK-NAC levels did not show a significant correlation with disease severity. This points towards the importance of monitoring vitamin B as a potential prognostic tool in managing GBS.
However, while vitamin B levels seemed to offer insight into GBS prognosis, elevated CK-NAC levels did not show a significant correlation with disease severity. This points towards the importance of monitoring vitamin B as a potential prognostic tool in managing GBS.
Read More
User Reviews
USERS' SCORE
Good
Based on 23 Reviews
8.7
- All Reviews
- Positive Reviews
- Negative Reviews
9
Improved B12 levels
108 people found this helpful
The best B12 I have ever tried! I had a severe B12 deficiency for many years, and no prescription medication worked. I shifted to methylcobalamin, achieving stable levels of 700-800 nmol/L. I recommend a good B complex alongside B12 supplementation to avoid masking other deficiencies. Methylcobalamin has helped me significantly, and my bloodwork reflects the improvement.
Read More
9
Lowered homocysteine levels
72 people found this helpful
Vitamin B12 effectively reduces homocysteine levels, critical for cardiovascular health. My husband’s levels decreased from 12 μmol/L to 8 μmol/L after taking this supplement, showing improved digestibility compared to cyanocobalamin in multivitamins. We will continue using it, especially as we age.
Read More
9
Better sleep quality
27 people found this helpful
I had no effect on sleep disorders with cyanocobalamin, but methylcobalamin worked wonders. Since I started taking it, I have experienced proper sleep and feel more refreshed in the mornings. It suits me well.
Read More
9
Eliminated involuntary jerking
22 people found this helpful
As a vegan, I suffered from involuntary finger jerking due to B12 deficiency. After starting these B12 supplements, the symptoms ceased immediately. It appears these tablets effectively address my deficiency since my diet hadn't changed.
Read More
9
Improved mood stability
21 people found this helpful
For six years as a vegetarian, I experienced fatigue and mood instability due to a B12 lack. After starting methyl B12, I no longer feel unstable and my general well-being has improved. I should have bought more!
Read More
Frequently Asked Questions
6
Greater morning comfort
1 people found this helpful
After three days of taking this, I feel more comfortable upon waking. I plan to reorder soon as I've noticed a significant improvement in how I start my day compared to before.
9
Improved alertness
10 people found this helpful
I've taken Jarrow Methyl B-12 for 4-5 months and have noticed a significant difference in my alertness and focus during the day. The methyl formula truly makes a difference compared to other supplements I've tried.
9
Boosted energy levels
1 people found this helpful
After experiencing health problems, I realised I had a B-12 deficiency. Following positive reviews, I ordered this vitamin and saw a rapid improvement in my fatigue and sleep quality. My B-12 levels have improved, and I've noticed better memory and focus as a bonus!
9
Lowered homocysteine levels
1 people found this helpful
Methyl B12 is perfect for lowering homocysteine. Within a month, my levels improved from 12 to 5 units alongside methyl folate. The chewable tablets taste pleasant, and I am now a permanent customer.
9
Improved B12 levels
108 people found this helpful
The best B12 I have ever tried! I had a severe B12 deficiency for many years, and no prescription medication worked. I shifted to methylcobalamin, achieving stable levels of 700-800 nmol/L. I recommend a good B complex alongside B12 supplementation to avoid masking other deficiencies. Methylcobalamin has helped me significantly, and my bloodwork reflects the improvement.
9
Improved mood stability
21 people found this helpful
For six years as a vegetarian, I experienced fatigue and mood instability due to a B12 lack. After starting methyl B12, I no longer feel unstable and my general well-being has improved. I should have bought more!
9
Better sleep quality
27 people found this helpful
I had no effect on sleep disorders with cyanocobalamin, but methylcobalamin worked wonders. Since I started taking it, I have experienced proper sleep and feel more refreshed in the mornings. It suits me well.
9
Increased energy levels
4 people found this helpful
This product has significantly helped with my neurological issues and improved my energy. I'm using it alongside weekly injections of methylcobalamin B12, and it has made a remarkable difference for my deficiency.
7.5
Vegetarian necessity
1 people found this helpful
For vegans and vegetarians, it's essential to supplement with B12 to avoid the risk of pernicious anaemia. This product has helped me sleep better, enabling me to stop relying on over-the-counter sleep aids. I’ve enjoyed great results after using it for many years.
6
Child's taste preference
1 people found this helpful
I started giving my child B12 supplements after her autoimmune disorder diagnosis, as those with autoimmunity often experience B12 deficiency. I’m unsure of its direct effects, but it hasn’t caused any harm, and she enjoys the taste. I’ll keep purchasing it. Notably, some B12 brands struggle with moisture; Jarrow remains excellent while others have deteriorated.
7.5
Effective treatment confirmed
1 people found this helpful
My spouse utilised this to raise his B12 levels alongside a B vitamin complex. Subsequent tests confirmed its effectiveness, and we are satisfied, ordering regularly. The tablets are of medium size and dissolve well.
9
Increased energy levels
1 people found this helpful
I love Jarrow Formulas Methyl B-12 1000mcg! I wish it came in larger bottles since I take four daily and usually order four smaller ones. Combined with Coenzyme B Complex, it has significantly improved my B12 and B5 levels, making me feel better within a day.
9
We examined a fascinating case of a 54-year-old man experiencing the rare overlap of Guillain-Barré Syndrome (GBS) and autoimmune gastritis. After a thorough medical evaluation, which included MRI and biopsy, he was diagnosed with both GBS and a vitamin B12 deficiency linked to atrophic gastritis.
Treatment with intravenous immunoglobulin and methylcobalamin (vitamin B12) led to substantial improvement in his symptoms. This case highlights the importance of recognizing potential nutrient deficiencies, especially those impacting autoimmune disorders like GBS and autoimmune gastritis.
Treatment with intravenous immunoglobulin and methylcobalamin (vitamin B12) led to substantial improvement in his symptoms. This case highlights the importance of recognizing potential nutrient deficiencies, especially those impacting autoimmune disorders like GBS and autoimmune gastritis.
9.5
Vitamin B12 supplementation benefits autoimmune patients
We explored the impact of vitamin B12 on patients with autoimmune disorders, particularly those experiencing symptoms often attributed to their underlying conditions. The study presented three cases of individuals with neuropathic pain, depression, fatigue, and muscle weakness, who had their symptoms initially misattributed to rheumatic diseases.
Upon starting vitamin B12 supplementation, these patients showed nearly complete resolution of their symptoms, highlighting the potential benefits of this vitamin in treating related health issues. Interestingly, several participants did not display obvious deficiencies in vitamin B12 levels according to lab tests, suggesting that even those who appear to have sufficient levels could still benefit from supplementation.
Furthermore, we delved into research indicating the nerve-protective properties of vitamin B12, which could play a crucial role in managing pain and neuropathy associated with long-standing rheumatic diseases. Therefore, we recommend that healthcare providers consider checking vitamin B12 levels early in the diagnostic journey for autoimmune conditions, and think about offering supplementation regardless of laboratory findings.
Upon starting vitamin B12 supplementation, these patients showed nearly complete resolution of their symptoms, highlighting the potential benefits of this vitamin in treating related health issues. Interestingly, several participants did not display obvious deficiencies in vitamin B12 levels according to lab tests, suggesting that even those who appear to have sufficient levels could still benefit from supplementation.
Furthermore, we delved into research indicating the nerve-protective properties of vitamin B12, which could play a crucial role in managing pain and neuropathy associated with long-standing rheumatic diseases. Therefore, we recommend that healthcare providers consider checking vitamin B12 levels early in the diagnostic journey for autoimmune conditions, and think about offering supplementation regardless of laboratory findings.
References
- Jatav VS, Sardana V, Bhushan B, Maheshwari D, Garg S, et al. Correlation of Serum Vitamin B and Muscle Enzyme (CK-NAC) Level with Severity of Guillain-Barre Syndrome and Its Prediction in Respiratory Failure. J Assoc Physicians India. 2025;73:48. 10.59556/japi.73.0892
- Mesgarankarimi A, Rezapour M, Tabrizi N. A long-standing undiagnosed case of vitamin B12 deficiency: a case report. J Med Case Rep. 2025;19:151. 10.1186/s13256-025-05149-7
- Ma XY, Hao Y, Xie YH, Cao Q, Sun DF, et al. Risk Factors Analysis and Predictive Model Construction for Autoimmune Gastritis: A Nationwide Multicenter Case-Control Study in China. J Gastroenterol Hepatol. 2025. 10.1111/jgh.16912
- Mswelo VE, David MM, Banturaki A, Munyambalu DK, Hassan HA, et al. Rural health challenges in Western Uganda: pernicious anemia masquerading as recurrent lower limb weakness-a case report. J Med Case Rep. 2025;19:60. 10.1186/s13256-025-05095-4
- Xiang H, Cai M. Coexistence of Guillain-Barré Syndrome and Subacute Combined Degeneration of the Spinal Cord Due to Autoimmune Gastritis: A Case Report and Literature Review. Cureus. 2024;16:e63084. 10.7759/cureus.63084
- Pluvinage JV, Ngo T, Fouassier C, McDonagh M, Holmes BB, et al. Transcobalamin receptor antibodies in autoimmune vitamin B12 central deficiency. Sci Transl Med. 2024;16:eadl3758. 10.1126/scitranslmed.adl3758
- Subtil J, Carvalho R, Rebelo AF, Subtil P. Autoimmune Polyglandular Syndrome Type 3: A Case Report. Cureus. 2024;16:e76152. 10.7759/cureus.76152
- Mansour M, Shamasnah A, Alsaadi D, Abu Saif S, Krama A. Evans syndrome as a presentation in systemic lupus erythematous, coexisting with Hashimoto's thyroiditis and pernicious anemia: a case report. J Med Case Rep. 2024;18:643. 10.1186/s13256-024-05002-3
- Hijjawi N, Tout FS, Azaizeh B, Aljaafreh B. The role of vitamins D, B12, C, and K in modulating inflammation and disease management in rheumatoid arthritis: a comprehensive review. Clin Rheumatol. 2025;44:591. 10.1007/s10067-024-07285-9
- Lang C, Huang P, Gao J, Chen Y, He Z. Co-existence of autoimmune polyglandular syndrome type 3b and undifferentiated connective tissue disease with subacute combined degeneration of spinal cord in children: a case report and literature review. BMC Pediatr. 2024;24:817. 10.1186/s12887-024-05262-4
- Haddad F, Boukhal Z, El Rhaoussi FZ, Tahiri M, Hliwa W, et al. Neurological and Cardiovascular Complications Revealing Biermer's Disease: A Case Report. Cureus. 2024;16:e58601. 10.7759/cureus.58601
- Fernandez I, Touzot F. Looking for ALPS: The value of a combined assessment of biochemical markers. Pediatr Allergy Immunol. 2024;35:e14135. 10.1111/pai.14135
- Yamada H, Toko M, Nakamori M, Ueno H, Aoki S, et al. Progressive multifocal leukoencephalopathy associated with systemic lupus erythematosus: longitudinal observation of lymphocytes, JC virus in cerebrospinal fluid, and brain magnetic resonance imaging. J Neurovirol. 2024;30:197. 10.1007/s13365-024-01203-0
- Yang CW, Hsu HY, Lee YZ, Lee SJ. Vitamin B12 inhibits peptidylarginine deiminases and ameliorates rheumatoid arthritis in CAIA mice. Biochem Biophys Res Commun. 2024;704:149668. 10.1016/j.bbrc.2024.149668
- Dułak NA, Rytlewska M, Jaskólska M, Chmielewski M. A new perspective on vitamin B12 deficiency in rheumatology: a case-based review. Rheumatol Int. 2024;44:737. 10.1007/s00296-024-05539-y
