Vitamin B12 Deficient? You May Not Need That Shot!

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Dr. Mark Ratner Headshot

By Mark Ratner, MD, Chief Science Officer, Theralogix and Andie Sherer, RD, Theralogix

Vitamins and minerals are the unsung heroes in your body. Each nutrient has a different role, yet all come together in perfect harmony to keep your body running properly. There is no single nutrient that claims the title of “most important,” but vitamin B12 certainly ranks near the top. 

Why is vitamin B12 so essential? How can you boost vitamin B12 in your diet? Do you need a vitamin B12 supplement? 

What is vitamin B12? 

Vitamin B12 is a water-soluble vitamin that helps produce healthy red blood cells, synthesize DNA (the genetic material in your cells), and support healthy nerve function. Healthy levels of vitamin B12 can also help support energy levels, but that doesn’t necessarily mean that you need to load up on vitamin B12. All eight B vitamins are involved in energy metabolism, but there is no evidence that getting more vitamin B12 than you need will give you extra energy. 

How much vitamin B12 do you need? 

Vitamin B12 is an extremely vital nutrient, but your body does not need a large amount to get the job done. The Recommended Dietary Allowance (RDA) for most adults is just 2.4 micrograms of vitamin B12 each day. Unlike most other water-soluble vitamins, your body stores vitamin B12 in your liver. Although it can take several years to deplete your vitamin B12 stores, it is still important to make vitamin B12 a regular part of your diet or supplement routine. 

Where is vitamin B12 in your diet?

Vitamin B12 is found mostly in animal sources like fish, meat, poultry, eggs and dairy products. You can also find this vitamin in some fortified foods, such as nutritional yeast, some plant-based milks, and ready-to-eat cereals. 

Do I need vitamin B12 supplements?

Some populations may have trouble meeting their vitamin B12 needs through food alone, have certain conditions that make it more difficult to absorb vitamin B12, or take certain medicines that deplete this nutrient. In these cases, a vitamin B12 supplement can help support healthy vitamin B12 levels. 

You can get extra vitamin B12 in two main ways: oral pills (nutritional supplements) or intramuscular injections (often called ‘B12 shots’). Both forms come in various doses, so make sure you discuss your specific needs with your healthcare provider. 

Which is better: vitamin B12 supplements or shots? 

A recent Cochrane Review suggests that vitamin B12 supplements are as effective as vitamin B12 shots in achieving a healthy vitamin B12 level. Vitamin B12 supplements also offer a few more advantages: 

  • They are less expensive than vitamin B12 shots. Although cost is variable based on your location, healthcare provider, and insurance, most vitamin B12 injections range between $50-250 per shot. Vitamin B12 supplements, on the other hand, average $0.07-0.33 per day. 
  • They do not require a prescription, whereas B12 shots are typically available by prescription only.
  • They are often more convenient. While vitamin B12 shots generally require a visit to your
    healthcare provider, you can take vitamin B12 supplement in the comfort of your own home. You can even order a high-quality vitamin B12 supplement online and have it delivered to your door.

If you choose to take a vitamin B12 supplement, make sure you choose a high-quality product with a NSF International or USP seal on the bottle. This ensures that your supplement contains the ingredients listed on the label at the right dose, and that it is free of harmful contaminants. A unique supplement, and one that I personally take and recommend to patients, is Remplir, which combines two forms of vitamin B12 called methylcobalamin and cyanocobalamin with chelated magnesium to provide optimal absorption of the nutrients. Additionally, Remplir is dye-free, gluten-free, vegan and certified by NSF International for purity and quality.

For those who have difficulty absorbing vitamin B12, supplements are still very effective.Vitamin B12 from food is bound to protein and requires two steps to be absorbed. First, stomach acid is needed to separate the vitamin from the protein. Second, the “free” B12 combines with a protein made in the stomach called intrinsic factor (IF), and they are absorbed together in your intestines. Vitamin B12 from a supplement only requires the second step. People who don’t make enough IF have a difficult time absorbing vitamin B12 effectively. 

Many believe that intramuscular vitamin B12 shots are superior because they bypass the digestive system completely. But remember, the human body is resilient and clever. Even without intrinsic factor, your body can passively absorb about 1% of vitamin B12 from supplements. This means that high-dose B12 supplements can help achieve healthy vitamin B12 levels in these individuals. 

Many vitamin B12 supplements contain 500 to 2000 mcg per pill. That seems like a large amount given that the RDA is set at 2.4 mcg per day, but even at high doses, vitamin B12 is considered safe because your body does not store more than it needs. 

Without enough vitamin B12, your body has a hard time staying in perfect harmony. It is like you are missing a note or playing off-key. If you struggle to get enough vitamin B12 through your diet alone or have issues with absorption, discuss with your healthcare team to determine the best method of supplementation for you. 

Biography: Mark Ratner, MD, is the chief science officer at Theralogix, and works with Andie Sherer, RD at Theralogix, a health and wellness company founded by a team of physicians and scientists committed to developing evidence-based, independently certified nutritional supplements. 

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