b12 injection diarrhea Vitamin B-12 3000 mcg Injection, 100 mL EllieMD | B12 (Methylcobalamin) Injection

When Not to Use: Avoid in cases of hypersensitivity to B vitamins or related compounds

On average, adults require approximately 1.5 micrograms of vitamin B12 per day

Tom Biernacki, DPM Board-Certified Podiatrist Last updated April 6, 2026 Medically reviewed by Dr

Other Causes of Black Stool While iron supplements are a common cause, black stool can also result from other factors, including: Consuming dark-colored foods such as beetroot, blueberries, black licorice, or large amounts of red meat Certain medications including bismuth subsalicylate or activated charcoal Underlying health issues such as stomach ulcers, gastrointestinal bleeding, or infections Identifying whether black stool is due to iron supplementation or another cause is important

Methylcobalamin is known to promote methylation, reduce homocysteine, support brain & nerve health, and positively affect anemia as well as the circulatory & immune systems