What is Vitamin B12? Everything You Need to Know

Vitamin B12, also known as cobalamin, is a vital nutrient your body needs to stay healthy and strong. It is a part of the group of B vitamins. It plays a critical role in energy production, red blood cell formation, nerve health, and DNA synthesis.

In this article, you’ll know what vitamin B12 does, why it matters, where to get it, how much you need, and what happens if you don’t have enough.

What is Vitamin B12?

Vitamin B12, an important water-soluble vitamin, plays a role in numerous functions in your body. Its key roles include:

• Making healthy red blood cells

• Keeping your brain and nerves working well

• Helping your body make DNA, which is the genetic material in every cell

Vitamin B12 acts as a helper for certain enzymes in your body, which means it helps chemical reactions happen so your body can work properly.

Why is Vitamin B12 Important?

Vitamin B12 is important for everyone, especially for:

• Children, so they can grow and develop normally

• Adults, to keep their brain sharp and their body energized

• Pregnant women, to help their baby’s brain and body grow the right way

If you don’t get enough vitamin B12, you can have alarming signs of B12 deficiency like feeling tired, weak, or dizzy. It can also affect your memory and mood, and in severe cases, it can cause nerve damage.

How Much Vitamin B12 Do You Need?

The daily requirement for vitamin B12 varies based on your age. Here are the recommended amounts for each age group:

Most people get enough vitamin B12 from food, but some people may need to take a Vitamin B12 supplement, especially older adults or those with health problems.

Where Can You Find Vitamin B12?

Vitamin B12 is found mostly in foods that come from animals, such as:

• Meat (beef, pork, chicken)

• Fish and shellfish

• Eggs

• Milk, cheese, and yogurt

Some foods, like breakfast cereals, have vitamin B12 added to them. If you don’t eat animal foods (for example, if you are vegan), you may need to take a vitamin B12 supplement or eat foods that have B12 added.

👉 Want to explore food options in detail? Check out our Top 10 Great Food Sources of Vitamin B12.

👉 For plant-based eaters, don’t miss our guide on Top 7 Great Food Sources of Vitamin B12 for Vegetarians and Vegans.

What Happens If You Don’t Get Enough?

If you don’t get enough vitamin B12, you might feel tired and sick. This happens because your body has a problem called B12 deficiency.

 Symptoms can include:

• Feeling very tired or weak

• Pale or yellow skin

• Shortness of breath

• Headaches

• Trouble with memory or thinking

• Mood changes, like feeling sad or confused

• Numbness or tingling in hands and feet

In children, not enough vitamin B12 can slow down growth and development. If the deficiency is not treated well, it can cause serious and sometimes permanent health problems.

Who is at Risk for Vitamin B12 Deficiency?

You may be at risk if you:

• Don’t eat animal foods (vegetarian or vegan diets)

• Have trouble absorbing nutrients (for example, due to stomach or gut problems)

• Are an older adult

• Take certain medicines that affect B12 absorption

If you think you might not be getting enough vitamin B12, talk to your doctor. A simple blood test can check your vitamin B12 level. 

How Can You Prevent Vitamin B12 Deficiency?

• Eat a balanced diet with foods rich in vitamin B12

• If you don’t eat animal foods, choose B12-fortified foods or take a supplement

• Get regular check-ups if you are at higher risk

Summary

Vitamin B12 is a key nutrient that helps your body make red blood cells, keeps your nerves and brain healthy, and supports growth and development. You can get it from animal foods or supplements. Not getting enough can make you feel tired, weak, and even cause nerve or memory problems. Eating a healthy diet and consulting with your doctor can help you maintain good health and overall well-being.