Supplement Facts
Serving Size: 1 Tablet
Amount Per Serving
%DV
Vitamin B-12 (as Cyanocobalamin)
2,500 mcg
104,167%
The product is found useful for the following medical conditions
Leg Cramps details
SCIENTIFIC SCORE
No researches found
N/A
USERS' SCORE
Good
Based on 2 Reviews
8.6
9
Disappearing leg cramps
Most Useful Review
It's astonishing! The quality and ingredients are excellent, and with 110 tablets, it’s better than pills. I experienced numbness in my hands and legs, but thankfully, that's gone. Folic acid is important, especially for pregnant women. My energy improved significantly, and the metabolism is superb. It tastes great too, much better than swallowing a pill!
Updated: Mar 2026
Chronic Fatigue Syndrome details
SCIENTIFIC SCORE
Questionable
Based on 7 Researches
6.4
USERS' SCORE
Good
Based on 3 Reviews
8.5
0
Vitamin B12 ineffective for CFS
We explored the effectiveness of high-dose vitamin B12 injections on chronic fatigue syndrome (CFS) through two case reports that utilized N of 1 trials. This approach allowed us to make tailored treatment decisions based on individual responses to the therapy.
In one case, we found that high-dose vitamin B12 injections did not yield positive results, leaving the patient without significant relief from their symptoms. Conversely, in another case, we observed that nimodipine proved to be a very effective treatment for that patient’s chronic fatigue.
These findings suggest that while vitamin B12 may not be helpful for everyone suffering from CFS, other treatments like nimodipine can be beneficial. Thus, personalized treatment strategies are key in managing this complex and varied condition.
In one case, we found that high-dose vitamin B12 injections did not yield positive results, leaving the patient without significant relief from their symptoms. Conversely, in another case, we observed that nimodipine proved to be a very effective treatment for that patient’s chronic fatigue.
These findings suggest that while vitamin B12 may not be helpful for everyone suffering from CFS, other treatments like nimodipine can be beneficial. Thus, personalized treatment strategies are key in managing this complex and varied condition.
9
Improved sleep quality
Most Useful Review
1 people found this helpful
In recent years, I have experienced chronic fatigue and nerve tingling, which have impeded my normal work activities. The doctor suggested a higher dosage of vitamin B12, and after over a month, the nerve pain gradually vanished. I now enjoy good sleep quality and feel less fatigued. This is vital for my health. 21st Century B12 is a high-dose and cost-effective product that I will continue to use.
Updated: Apr 2025
High Cholesterol details
SCIENTIFIC SCORE
Possibly Effective
Based on 10 Researches
7.5
USERS' SCORE
Good
Based on 2 Reviews
8.5
9
We focused on whether white button mushrooms could help lower cholesterol levels and blood sugar in rats. In our study, we found that after three weeks of the mushroom powder, diabetic rats showed significant drops in glucose and triglyceride levels.
Furthermore, in hypercholesterolemic rats, a four-week treatment led to impressive reductions in total cholesterol and LDL cholesterol. Overall, these findings suggest that white button mushrooms may have beneficial effects on cholesterol and blood sugar management, at least in rat models.
Furthermore, in hypercholesterolemic rats, a four-week treatment led to impressive reductions in total cholesterol and LDL cholesterol. Overall, these findings suggest that white button mushrooms may have beneficial effects on cholesterol and blood sugar management, at least in rat models.
9
Heart health improved
Most Useful Review
The quality is excellent, with wonderful ingredients and suitable age composition. Fish oil and omega-3 help reduce high cholesterol, increase hair density, and protect the heart from inflammation. I’ve noticed a strengthening effect on my body.
Updated: Mar 2026
Mild Cognitive Impairment details
SCIENTIFIC SCORE
No researches found
N/A
USERS' SCORE
Good
Based on 3 Reviews
8.5
9
Enhanced vitality noted
Most Useful Review
3 people found this helpful
Vitamin B12 has been a revelation for me! After purchasing it based on positive reviews, I experienced a surge of energy, improved physical activity, and even healthier hair. This vitamin is crucial for myelin synthesis, which protects nerve fibers and aids signal transmission. I learned that it plays a significant role in blood circulation alongside iron, assisting in red blood cell division, crucial for constant oxygen flow. B12 also helps eliminate harmful homocysteine, protecting blood vessels and potentially preventing conditions like Alzheimer's disease and dementia. Additionally, it supports various functions, including mood and detoxification. If this review helps you, I’m pleased! Thank you to those who support my feedback.
Updated: Apr 2025
Sleep Apnea details
SCIENTIFIC SCORE
No researches found
N/A
USERS' SCORE
Good
Based on 4 Reviews
8.4
9
Cravings reduced
Most Useful Review
Excellent! My sleep improved by the third day, and I stopped craving sweets from the first day due to my sleep apnea. The sublingual lozenges are a very convenient and effective solution.
Updated: Mar 2026
Bone Pain details
SCIENTIFIC SCORE
No researches found
N/A
USERS' SCORE
Good
Based on 2 Reviews
8.3
7
Nerve support
Most Useful Review
This is beneficial for nerve and bone patients, delivering good results. I recommend taking it once daily.
Updated: Mar 2026
Cardiovascular Disease details
SCIENTIFIC SCORE
Questionable
Based on 9 Researches
6.7
USERS' SCORE
Good
Based on 3 Reviews
8.3
8
We examined the role of vitamin B status on mortality rates, focusing on cardiovascular disease. Using data from over 12,000 adults, we found that higher scores on the combined vitamin B status indicator (3cB) were linked to lower risks of dying from cardiovascular issues. Specifically, individuals with lower 3cB scores faced significantly higher risks of mortality. This suggests that maintaining adequate vitamin B levels could potentially play an important part in reducing cardiovascular disease-related deaths.
7.5
Increased energy
Most Useful Review
1 people found this helpful
This product is excellent. I've noticed a boost in energy and it has improved my cardiovascular health. The taste is pleasant, and I would recommend it to anyone looking to enhance their vitality.
Updated: Mar 2026
Osteoporosis details
SCIENTIFIC SCORE
Questionable
Based on 4 Researches
5.8
USERS' SCORE
Good
Based on 2 Reviews
8.3
7
We explored how vitamin B12 affects spinal fractures in patients with osteoporosis, a condition that significantly increases the risk of these injuries. Our investigation involved 105 participants diagnosed with osteoporosis. We assessed clinical data alongside blood levels of several vitamins, including vitamin B12, to understand their connection to spinal fractures.
Our analysis revealed a substantial relationship between elevated vitamin B12 levels and the incidence of spinal fractures. We found that not only was there a notable association with spinal fractures, but higher vitamin B12 was also linked to a shorter time before a recurrence of fractures occurred. These findings suggest that as vitamin B12 levels rise, the risk for spinal fractures in osteoporosis patients increases, which indicates a potentially serious concern for these individuals.
While vitamin B9 also showed some association, it was vitamin B12 that stood out in both our logistic regression analyses. Overall, our results suggest that monitoring and perhaps addressing vitamin B12 levels could be crucial for managing patients’ health and preventing further complications from osteoporosis.
Our analysis revealed a substantial relationship between elevated vitamin B12 levels and the incidence of spinal fractures. We found that not only was there a notable association with spinal fractures, but higher vitamin B12 was also linked to a shorter time before a recurrence of fractures occurred. These findings suggest that as vitamin B12 levels rise, the risk for spinal fractures in osteoporosis patients increases, which indicates a potentially serious concern for these individuals.
While vitamin B9 also showed some association, it was vitamin B12 that stood out in both our logistic regression analyses. Overall, our results suggest that monitoring and perhaps addressing vitamin B12 levels could be crucial for managing patients’ health and preventing further complications from osteoporosis.
7.5
Supports bone health
Most Useful Review
The price is reasonable. This company faces criticism for not registering its products as non-GMO. The effect is beneficial if there's no absorption issue, particularly in the elderly; a deficiency of pepsin in the stomach means pills won't work. In such cases, B12 injections are necessary. Vitamin B12 supports nerves and blood cells. It's essential for daily health, aiding in red blood cell formation, maintaining nerve cell health, and helping DNA production. Deficiency leads to noticeable symptoms. It's advisable to take B12 with folic acid. Nutritionists highlight its importance for mood regulation and mental health, as B12 contributes to neurotransmitter production. This may explain its potential benefits for those with depression or anxiety. B12 also supports healthy fetal development and helps prevent osteoporosis.
Updated: Apr 2025
Flu details
SCIENTIFIC SCORE
No researches found
N/A
USERS' SCORE
Good
Based on 4 Reviews
8.2
9
High energy
Most Useful Review
I like it very much; it is a high-quality product with good ingredients. The size is perfect, and the folic acid is great. It gives me high energy, and the niacin flush is good. The packaging is perfect. It is very effective with good potency, improving my nervous system and metabolism. Plus, it tastes good.
Updated: Mar 2026
Anemia details
SCIENTIFIC SCORE
Moderately Effective
Based on 21 Researches
8.2
USERS' SCORE
Good
Based on 17 Reviews
8.1
9.5
We explored the case of a 23-month-old boy suffering from severe pancytopenia linked to Imerslund-Gräsbeck syndrome, a rare condition caused by an inability to absorb vitamin B12. Upon diagnosis, the boy received vitamin B12 replacement therapy, which effectively addressed his symptoms and improved his health.
This case highlights the significance of early detection and treatment of IGS to avoid potential neurological damage. It's crucial to recognize this condition, even when neurological symptoms are absent, to provide timely care.
This case highlights the significance of early detection and treatment of IGS to avoid potential neurological damage. It's crucial to recognize this condition, even when neurological symptoms are absent, to provide timely care.
10
Cured anemia
Most Useful Review
2 people found this helpful
I bought this due to severe anaemia. Initially, I took 1500mcg, but it wasn't effective, so I switched to 2500mcg. Blood tests confirm my anaemia has resolved, and I’ve recommended it to my aunt for her neuralgia; she reported reduced pain.
Updated: Mar 2026
Depression details
SCIENTIFIC SCORE
Questionable
Based on 21 Researches
6.9
USERS' SCORE
Good
Based on 8 Reviews
8.1
8
We explored the connection between vitamin B levels and depression in older adults over four years. Our study followed nearly 3,850 participants and found that those with low blood levels of vitamin B were significantly more likely to report depressive symptoms. Specifically, individuals with low vitamin B had a 51% higher chance of developing depression compared to those with adequate levels.
However, we did not find any significant link between folate levels and depression. These insights suggest that boosting vitamin B might be a simple, cost-effective way to help improve mental health in older adults.
However, we did not find any significant link between folate levels and depression. These insights suggest that boosting vitamin B might be a simple, cost-effective way to help improve mental health in older adults.
9
Resolved depression
Most Useful Review
1 people found this helpful
Excellent! B12 is a fantastic product that I take alongside folic acid and I'm now fine with depression. I would 100% recommend it. The quality and price are great. It has a pleasant raspberry flavour and aroma. The small pills are easy to swallow. Many thanks to the iHerb team.
Updated: Apr 2025
Dizziness details
SCIENTIFIC SCORE
Moderately Effective
Based on 17 Researches
8.4
USERS' SCORE
Good
Based on 9 Reviews
8.1
9.5
We examined a unique case involving a 28-year-old male who experienced dizziness related to severe anemia from low vitamin B12 levels.
After treatment with daily vitamin B12 injections, his symptoms and lab values significantly improved, indicating a positive response to the treatment.
Despite the rare nature of his condition—seronegative pernicious anemia—the results suggest that B12 can effectively alleviate dizziness stemming from anemia in similar cases.
After treatment with daily vitamin B12 injections, his symptoms and lab values significantly improved, indicating a positive response to the treatment.
Despite the rare nature of his condition—seronegative pernicious anemia—the results suggest that B12 can effectively alleviate dizziness stemming from anemia in similar cases.
9
Energy restored
Most Useful Review
4 people found this helpful
B-12 is essential! A deficiency leads to constant drowsiness, shortness of breath, and dizziness. B12 protects nerve fibres, ensuring the nervous system functions properly. I used B12 for my anaemia, alongside iron and vitamin C. A month later, my haemoglobin was 131. I felt more energetic, and the drowsiness and dizziness had gone. The taste is pleasantly fruity!
Updated: Apr 2025
Knee Pain details
SCIENTIFIC SCORE
No researches found
N/A
USERS' SCORE
Good
Based on 4 Reviews
8
7.5
Effective for pain
Most Useful Review
2 people found this helpful
I train at the gym daily, but I often suffer from injuries. I take B12 for knee pain and other joint issues, and it seems effective. Previously, a doctor administered a B12 injection for back pain, which led me to consider it as a supplement. I invested in a high-compound product from iHerb. If I feel discomfort, I take it right away, and it typically alleviates the pain in 2-3 days while also applying a compress.
Updated: Apr 2025
Back Pain details
SCIENTIFIC SCORE
Moderately Effective
Based on 17 Researches
8.3
USERS' SCORE
Medium or Average
Based on 14 Reviews
6.5
9
We evaluated the effectiveness of intramuscular vitamin B12 in treating low back pain among 60 patients aged 18 to 65 with mechanical pain lasting at least six months.
In this double-blind, placebo-controlled study, both groups showed improvement in pain levels. However, those receiving B12 had a more significant reduction in pain and dependence on pain medication compared to the placebo group.
Overall, B12 appears to be a safe option for alleviating low back pain, helping to reduce discomfort and medication use for those without nutritional deficiencies.
In this double-blind, placebo-controlled study, both groups showed improvement in pain levels. However, those receiving B12 had a more significant reduction in pain and dependence on pain medication compared to the placebo group.
Overall, B12 appears to be a safe option for alleviating low back pain, helping to reduce discomfort and medication use for those without nutritional deficiencies.
9
Quick pain relief
Most Useful Review
3 people found this helpful
I woke up with severe back pain that made it impossible to move. By the third day of taking the vitamin, the pain lessened significantly, and after ten days, it vanished completely. My sleep improved, although I still take magnesium. The tablets dissolve quickly under the tongue and taste like fruity ascorbic acid. They truly work, and I didn't expect such a swift effect.
Updated: Mar 2026
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