What is vitamin B?

Vitamin B is a group of vitamins that help your body's metabolism. The 'B-group' or 'B-complex' of vitamins makes up 8 out of 13 essential vitamins.

B-group vitamins are all water-soluble (dissolve in water), which means that they can't be stored in your body. So, foods containing vitamin B must be eaten regularly as part of a healthy diet.

The B-group of vitamins include:

• thiamin (vitamin B1)
• riboflavin (vitamin B2)
• niacin (vitamin B3)
• pantothenic acid (vitamin B5)
• pyridoxine (vitamin B6)
• biotin (vitamin B7)
• folate (vitamin B9)
• cobalamin (vitamin B12)

Why is vitamin B important for my health?

Each of the B-group vitamins plays a critical role in keeping you healthy.

Vitamin	Role in your body
Thiamin	Helps your body break down and release energy from food. Keeps your nervous system healthy.
Riboflavin	Keeps your skin, eyes and nervous system healthy. Helps your body release energy from food.
Niacin	Helps your body release energy from food. Keeps your nervous system and skin healthy.
Pantothenic acid	Helps your body release energy from food.
Vitamin B6	Helps your body to use and store energy from protein and carbohydrates in food. Helps your body make haemoglobin (which carries oxygen around your body in red blood cells).
Biotin	Helps your body make fatty acids. Help your nervous system function.
Folate	Helps your body form healthy red blood cells. When pregnant, lowers the risk of neural tube defects, such as spina bifida, in your baby.
Vitamin B12	Helps make red blood cells and keeps your nervous system healthy. Helps release energy from food. Helps your body to use folate.

What foods are high in vitamin B?

Vitamin B is naturally found in many foods.

In Australia, manufacturers must also add thiamine and folic acid (man-made folate) to wheat flour that is used to make bread. Some manufacturers may also choose to add vitamin B to their product — such as breakfast cereals. You can find this information on the food label.

Vitamin	Food sources
Thiamin	Peas, bananas, oranges, nuts, wholegrain breads, liver and some fortified cereals.
Riboflavin	Milk, eggs, plain yoghurt, cheese, meats, leafy green vegetables, mushrooms and some fortified cereals.
Niacin	Meat, fish, mushrooms, potatoes and eggs.
Pantothenic acid	Chicken, beef, liver, eggs, broccoli, mushrooms, avocado and tomatoes.
Vitamin B6	Meat, poultry, some fish, peanuts, tofu and soy products, oats, bananas, watermelons, milk and some fortified cereals.
Biotin	Whole grains, organ meats, egg yolks, soybeans, and fish. Biotin is also made by bacteria in your bowel.
Folate	Liver, chickpeas, kidney beans, peas, broccoli, brussels sprouts, asparagus, leafy green vegetables and fortified breads and cereals.
Vitamin B12	Meat, fish, eggs, milk, cheese and some fortified cereals, plant milks, and meat substitute products.

To get a diet high in B vitamins, try to eat a wide variety of fresh, unprocessed foods. Try to eat a mixture of:

• vegetables
• grains and cereals
• lean meats and other proteins
• dairy
• fruits

How much vitamin B do I need?

The recommended amount of each B vitamin may depend on your age, sex and life stage. For example, pregnant people, breastfeeding people and children all need different doses of each individual vitamin B.

Most people should be able to get all the vitamin B they need by eating a varied diet.

Recommended dietary intake

Vitamin	Adult males	Adult females
Thiamin	1.1mg/day	1.2mg/day
Riboflavin	19 to 70 years = 1.1mg/day 70yrs+ = 1.3mg/day	19 to 70 years = 1.3mg/day 70yrs+ = 1.6mg/day
Niacin	14mg/day	16mg/day
Pantothenic acid	6mg/day	4mg/day
Vitamin B6	19 to 50 years = 1.3mg/day 51years+ = 1.5mg/day	19 to 50 years = 1.3mg/day 51years+ = 1.7mg/day
Biotin	25µg/day	30µg/day
Folate	400µg/day	400µg/day
Vitamin B12	2.4µg/day	2.4µg/day

Can I have too little vitamin B?

It's possible not to get enough vitamin B in your diet. This usually happens if you're on a restrictive diet (such as vegans) or have a chronic (ongoing) health condition.

If you don't get enough vitamin B, you may be at risk of a vitamin B deficiency.

If you are worried that you don't get enough vitamin B, talk with your doctor or an accredited dietitian.

What happens if I have too much vitamin B?

Generally, the B vitamins aren't harmful when found naturally in your food.

However, you should be careful when taking supplements. Never take more than the recommended upper limit, unless told to do so by a doctor or dietitian.

Some vitamin B supplements cause toxicity when taken in excess.

Vitamin	Upper limit	Health risk
Thiamin	Not known	None from food.
Riboflavin	Not known	None
Niacin	35mg/day	Too many supplements can cause skin flushing, burning, tingling, and itching. It can also cause headaches, rashes, and dizziness.
Pantothenic acid	Not known	None
Vitamin B6	50mg/day	Nerve damage when taken at high doses for more than a year. Skin damage, sensitivity to sunlight, nausea, and heartburn.
Biotin	Not known	Too much through supplements may cause false hormone measurements.
Folate	1,000µg/day	High doses through supplements may increase your risk of colorectal cancer. It can also hide a vitamin B12 deficiency.
Vitamin B12	Not known	None

The best way for healthy people to get vitamin B is by eating a balanced diet.

Should I take vitamin B supplements?

Many over-the-counter multivitamins contain B vitamins. Each type of vitamin B has its own dosage. Do not double up on supplements. For example, if you take a multivitamin, check before you take a specific vitamin B supplement.

If you use over-the counter supplements, always read the doses on the bottle. Choose the supplement that suits your life stage and circumstance.

Always speak with your doctor or an accredited dietitian before taking a vitamin supplement. While supplements can support your diet, you should still eat healthily.

Vegan diet and vitamin B12 supplements

The Australian Dietary Guidelines advise that people following a vegan diet take a B12 supplement.

Pregnancy and folic acid supplements

Folate and folic acid are important in pregnancy because they can help prevent neural tube defects, such as spina bifida.

You should start taking a pregnancy specific folic acid supplement at least one month before you start trying to get pregnant. If you haven't been taking folic acid before getting pregnant, be sure to start now.

You should keep taking the supplement for at least the first trimester of your pregnancy.

Do vitamin B supplements cause side effects?

Some vitamin B supplements cause toxicity when taken in excess.

Vitamin B supplements can also interact with other medicines that you may take. It's important to speak to your doctor or pharmacist before taking supplements or starting a new medicine.

Resources and support

See the Australian Guide to Healthy Eating.

The Dietitians Australia website allows you to search for an Accredited Practising Dietitian.

You can also call the healthdirect helpline on 1800 022 222 (known as NURSE-ON-CALL in Victoria). A registered nurse is available to speak with 24 hours a day, 7 days a week.