Product name as reported
Vitamin B12: adverse event reports filed with FDA
2,197 reports list it as a suspect or interacting product, 2005–2026. Also reported as Vitamin B12 Nos, Vitamin B12 /00056201/, Vitamin B12 /00091801/.
- 2,197
- reports as suspect product
- 0% of all reports · about 103 a year
- 156
- reports, 12 months to June 2026
- 190 in the 12 months before
- 85.2%
- marked serious by the reporter
- 57.4% across all reports
- 15%
- record death among outcomes, as reported
- 330 reports · not verified by FDA
Between March 2005 and June 2026, 2,197 adverse event reports received by FDA list the product name "Vitamin B12" as reporters wrote it as a suspect or interacting product. Reports that mention it only as a concomitant medication (113,304) are left out of every figure here.
In the 12 months to June 2026, 156 reports listed it, down 18% from 190 in the 12 months before. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases. Over its reporting history that is about 103 reports a year and 0% of the 20,646,523 reports in the database. How many people take it is not in the data, so a count is not a rate of occurrence.
The MedDRA terms listed most often are drug ineffective (16.4%), hypertension (13.8%) and gastrooesophageal reflux disease (12.7%). A report can list several reactions, so shares add to more than 100%; 848 different terms appear across these reports. Drug ineffective is recorded in 16.4% of these reports, against 6.3% of all reports in the database.
85.2% of the reports are marked serious by the reporter; 15% record death among the outcomes and 46.3% record hospitalisation, as reported. 44.2% of the reports came from other health professionals, and the largest patient age group is 45 to 64 (31.8%). FDA states that "a causal relationship cannot be established between product and reactions listed in a report" and that for any given report "there is no certainty that a suspected drug caused the event."
Reports by month, five years
Reports by the month FDA received them. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases.
By year received
2026 covers reports received through June 2026 only.
Reactions recorded in the reports
share of Vitamin B12 reports recording the termall reports in the database
- Drug ineffectivethe medicine did not work as expected16.4%361
- Hypertensionhigh blood pressure13.8%304
- Gastrooesophageal reflux diseaseacid reflux12.7%278
- Headachehead pain12.5%274
- Dyspnoeashortness of breath11.9%261
- Off label useused for a purpose or in a way not on the label11.7%256
- Fatiguetiredness11.4%251
- Asthmaasthma11.2%247
- Wheezingwheezing10.4%228
- Fibromyalgia9.4%206
- Malaisegeneral feeling of being unwell9.1%201
- Arthralgiajoint pain7.8%172
- Pruritusitching7.8%171
- Painpain, site not specified7.7%170
- Somnolencedrowsiness7.6%166
- Hypoaesthesianumbness7.4%163
- Diarrhoealoose or frequent stools7.4%162
- Insomniadifficulty sleeping7.3%161
- Weight increasedweight gain7.1%157
- Vomitingbeing sick7.1%155
- Pyrexiafever6.9%152
- Nasopharyngitisa cold6.7%148
- Peripheral swellingswelling of the arms or legs6.7%147
- Urticariahives6.7%147
- Nauseafeeling sick6.6%144
- Condition aggravatedthe condition being treated got worse6.5%142
- Infusion related reactiona reaction during or soon after an infusion6.4%141
Top 30 of 848 MedDRA preferred terms recorded across these reports, with a plain-language gloss where one is available. One report can record several terms. The hollow bar is the share of all reports in the database; it describes the reports, not the patients. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic."
Outcomes recorded
Outcome flags as the reporter set them; a report can carry several, and "other serious" is FDA's own category for serious reports outside the named outcomes. Grey bar: all 20,646,523 reports. FDA has not verified any outcome and states that the reports "cannot be used to estimate the incidence of these events."
Patients and reporters
Patient age
Patient sex
Who reported
Age and sex as stated in the report; the reporter's qualification is the primary source recorded by FDA. 30.7% of reports give the United States as the country of the event or reporter.
Reason for use recorded
| Indication as recorded (MedDRA) | Reports | Share |
|---|---|---|
| Supplementation therapy | 63 | 2.9% |
| Vitamin b12 deficiency | 49 | 2.2% |
| Rheumatoid arthritis | 43 | 2% |
| Nutritional supplementation | 22 | 1% |
| Foetal exposure during pregnancy | 18 | 0.8% |
| Vitamin supplementation | 16 | 0.7% |
The indication field is filled in by the reporter and is often blank; shares are of all 2,197 reports.
Drugs most often listed in the same reports
| Drug (any role in the report) | Reports | Share of Vitamin B12 reports |
|---|---|---|
| Prednisone | 702 | 32% |
| Ergocalciferol | 674 | 30.7% |
| Folic acid | 553 | 25.2% |
| Vitamin c | 462 | 21% |
| Cyanocobalamin | 322 | 14.7% |
| Methotrexate | 303 | 13.8% |
| Humira | 293 | 13.3% |
| Pantoprazole | 287 | 13.1% |
| Calcium carbonate | 273 | 12.4% |
| Acetaminophen | 252 | 11.5% |
Other products listed in reports where Vitamin B12 is a suspect product, whatever their own role. Co-listing means the two were recorded together; it says nothing about either product's part in the event. Only the 2,500 most-reported names are counted here.
In context
| Measure | Vitamin B12 | All reports |
|---|---|---|
| Reports as suspect product | 2,197 | 20,646,523 |
| Share of that pool | — | 0% |
| Reports, latest 12 months | 156 | 1,332,454 |
| Marked serious | 85.2% | 57.4% |
| Death recorded among outcomes, per 1,000 reports | 150 | 91 |
| Hospitalisation recorded, per 1,000 reports | 463 | 213 |
| Consumer-filed share | 33.1% | 45.8% |
| Top term, share of reports | Drug ineffective 16.4% | 6.3% |
Shares are of reports, not of patients treated. The number of people taking a product is not in the data, so none of these figures is a rate, and differences between columns reflect who takes a product, who reports and how long it has been sold. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic."
Questions about Vitamin B12 reports
How many adverse event reports has FDA received for Vitamin B12?
2,197 reports list Vitamin B12 as a suspect or interacting product in the openFDA FAERS release of 28 Sep 2026, covering reports received through June 2026. 156 of them arrived in the latest 12 months. Another 113,304 list it only as a concomitant medication.
What reactions are recorded in Vitamin B12 reports?
drug ineffective (16.4%), hypertension (13.8%), gastrooesophageal reflux disease (12.7%), headache (12.5%) and dyspnoea (11.9%). These are MedDRA preferred terms coded from what the reporter described; a report can list several, and a term's presence is not a finding that Vitamin B12 was responsible.
How serious are the reports?
85.2% are marked serious by the reporter. Among the outcomes recorded, 15% of reports include death and 46.3% include hospitalisation. FDA has not verified these outcomes and states that the reports "cannot be used to estimate the incidence" of the events.
Who files these reports?
other health professional (44.2%), consumer or non-health professional (33.1%) and physician (17.7%). Most reports reach FDA through the manufacturer, which must forward reports it receives.
Are reports for Vitamin B12 rising?
156 reports in the 12 months to June 2026, down 18% from 190 in the 12 months before. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases. Counts also move with how many people take a product, its time on the market and publicity.
Do these reports show that Vitamin B12 was responsible for these reactions?
No. FDA states that "a causal relationship cannot be established between product and reactions listed in a report" and that for any given report "there is no certainty that a suspected drug caused the event." The reaction may relate to the condition being treated, to other medicines, or to something else.
Is this a list of the side effects of Vitamin B12?
No. It is a count of what was reported to FDA. The adverse reactions observed in clinical studies are printed on the FDA-approved label, which a pharmacist or clinician can go through with you.
How do I report an adverse event?
Consumers and health professionals can report to FDA through MedWatch (Form FDA 3500 online, or 1-800-FDA-1088), or to the manufacturer, which must pass reports on. See the guide on how to report.
Where this comes from. Counts are built from the openFDA Drug Adverse Event (FAERS) bulk export released 28 Sep 2026, which holds reports FDA received through 30 Jun 2026. Drug names are as reported, resolved to the brand or generic name on the FDA label where openFDA's harmonisation matched them; classes are the pharmacologic class (EPC) from the label and the National Drug Code Directory of 17 Sep 2026. A report counts here when it lists Vitamin B12 as a suspect or interacting product; reports listing it only as a concomitant medication (113,304) are excluded. No report narrative, lot number, patient detail or reporter identity is published. See the methodology and sources; FDA's record is authoritative, and corrections are handled within five working days.
Drug data (FAERS) through 30 Jun 2026; device data (MAUDE) through 31 Aug 2026. Not medical advice.