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Feeling Tired or Weak? You May Need More Vitamin B12

  • Category: LiveSmart
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  • Written By: Baldwin

foods with B12 in them

These are just some symptoms that can occur if you're lacking this essential nutrient.

Your body needs a variety of vitamins every day. Some of these are considered essential nutrients because your body cannot produce them on its own. The only way to get what your body needs is through food (or supplements). One such vitamin is B12 – also called cobalamin. This essential vitamin is critical in keeping the body healthy.

Vitamin B12 is a water-soluble vitamin that is not stored in the body. That means you need to consume enough of this vitamin each day to keep your body running optimally. The recommended dietary allowance (RDA) for vitamin B12 is 2.4 micrograms a day for most adults. If you don't get enough B12, you may experience symptoms that are just minor annoyances, but left untreated, a deficiency in this critical vitamin can lead to serious health problems.

What does vitamin B12 do?

Vitamin B12 plays a key role in how your nervous system operates. It supports the function of your nerve cells and is needed for the formation of red blood cells. It also plays a role in DNA synthesis. Vitamin B12 affects important functions of your heart, brain, nerves, bones, eyes and skin. It can also affect your energy levels.

What are signs that I need more vitamin B12?

These are some of the most common signs of a vitamin B12 deficiency:

  • Fatigue
  • Weakness
  • Numbness, tingling or a pins-and-needles feeling in your legs, feet or hands
  • Balance problems, including difficulty walking
  • Cognitive problems, including memory loss or difficulty with thinking or reasoning
  • Mouth sores or a swollen tongue
  • Pale or yellow skin
  • Painful joints
  • Depression
  • Muscle cramps
  • Anemia

Symptoms may come on gradually or appear suddenly. You may only have one symptom or experience more than one. Many symptoms may also be due to other health conditions. A blood test can check your B12 levels to see if you are deficient in this vitamin. Left untreated, vitamin B12 deficiency can cause severe neurological problems and blood diseases so symptoms should not be ignored.

Why am I deficient in vitamin B12?

Some people don't get enough vitamin B12 in their diets because of the foods they eat. For others, a deficiency may be caused by an inability of the body to effectively absorb vitamin B12 even when enough is consumed. Factors that may make it harder for your body to absorb B12 include advancing age, weight loss surgery, gastrointestinal disorders such as Crohn's or celiac disease, alcohol use disorder or certain medications, such as heartburn drugs.

How can I add more vitamin B12 to my diet?

Vitamin B12 is found naturally in animal products, including meat, poultry, fish, eggs and dairy products. It may also be added to other foods, such as fortified breakfast cereals and nutritional yeast. People who follow a primarily plant-based diet, including vegetarians and vegans, may not get enough B12 from their diets because it is not a naturally occurring vitamin in plant foods. If you cannot consume enough foods containing B12, a supplement may be needed.

Many people can get the vitamin B12 they need by taking a daily multivitamin. Standard multivitamins contain more than the RDA for this vitamin. If you have a serious B12 deficiency, you may need a daily high-dose vitamin B12 pill or weekly injections of B12. Talk to your doctor or a registered dietitian about what is right for you.

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Date Last Reviewed: February 15, 2024

Editorial Review: Andrea Cohen, Editorial Director, Baldwin Publishing, Inc. Contact Editor

Medical Review: Jane Schwartz, RDN, CLT

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