Vitamin B12Cyanocobalamin/Methylcobalamin

About Vitamin B12

B12 is needed for red blood cells and nerves, and a deficiency causes anemia and nerve damage. The NIH lists older adults with atrophic gastritis, people with pernicious anemia or past stomach or bowel surgery, and vegans among those most at risk.

Injections bypass the gut and are the usual treatment. The injection label calls oral absorption too undependable to rely on in pernicious anemia, an autoimmune disease, and says people treated with injections for it need them monthly for life. MedlinePlus notes that some people are adequately treated with large doses by mouth, and the NIH cites a review in which high oral doses raised blood levels about as well as injections; the choice is the prescriber’s.

The injection, 1,000 mcg per mL, goes into a muscle or deep under the skin. It is not used with a cobalt allergy, can rapidly damage the optic nerve in Leber’s hereditary optic neuropathy, and can drop potassium dangerously when severe anemia is treated.

The nasal spray, 500 mcg in one nostril weekly, is labeled to keep B12 up in pernicious anemia after injections, if the nerves are unaffected, and for other deficiencies; it is put off while the nose is congested or infected. Over-the-counter tablets and sublingual products are supplements, which the FDA does not approve; the NIH reports no difference between swallowed and sublingual forms, and no evidence that absorption varies by form. Hydroxocobalamin injection is another prescription form.

Taking Vitamin B12

How to take it

Injection: into a muscle or deep under the skin, never a vein, usually by a health professional, often frequently at first and then monthly. Spray: one spray in one nostril on the same day each week, with no hot food or drink for an hour before or after. Tablets: usually with a meal.

If you miss a dose

Missed injection appointment: call your prescriber as soon as possible. Spray or tablets: take it when you remember unless the next dose is almost due; then skip it.

Storage

Injection vials at room temperature, protected from light; spray devices upright in their carton; tablets tightly closed, away from heat and moisture. Keep all out of reach of children.

Interactions to know about

Metformin, proton pump inhibitors such as omeprazole and H2 blockers such as famotidine can lower B12 absorption, as can colchicine and heavy drinking for more than two weeks. Folic acid can hide a deficiency while nerve damage goes on. Tell the prescriber about Leber’s disease or a cobalt allergy.

This summarizes the official prescribing information. Your prescriber’s and pharmacist’s instructions, and the leaflet that comes with your medicine, take priority.

Why the cash price for Vitamin B12 differs from pharmacy to pharmacy

Cyanocobalamin injection has several makers, so a vial’s cash price is mostly each pharmacy’s fee and mark-up, and a clinic visit to give it is charged on top. The spray has few generic makers, and with Nascobal listed as discontinued, quotes depend on which generic a pharmacy can get. Over-the-counter B12 has no dispensing fee.

Ways to pay less for Vitamin B12 without insurance

• Ask the prescriber whether high-dose B12 by mouth would suit you.
• For injections, ask the clinic what it charges to give one, and have the pharmacy quote the vial.
• For the spray, ask whether the pharmacy can supply a generic.
• If your prescriber approves a supplement, the NIH reports no evidence that any form absorbs better than plain cyanocobalamin.
• Upload the prescription to Script Unlock so licensed pharmacies can quote their cash price. You pay the pharmacy directly.

Questions to ask your pharmacist about Vitamin B12

1. 1.Do I need injections, or could tablets work?
2. 2.How often do I need the injection or spray, and for how long?
3. 3.Do my metformin or acid-reducing medicines affect my B12?
4. 4.When will my B12 level and blood count be checked?

Related medications