Discover the Right Vitamin B Complex Dosage: The RDA for All 8 B Vitamins

vitamin B complex dosage

Sticking to your recommended vitamin B complex dosage isn’t always straightforward.

The vitamin B complex is a group of eight vitamins that play important roles in many body functions. Hitting your daily vitamin B complex dosage is essential for:

  • converting carbohydrates into energy
  • helping oxygen move around your circulatory system
  • the proper functioning of your brain and nervous system
  • keeping your eyes, skin and hair healthy
  • supporting your immune system

Your body can’t store most of the B vitamins (except for biotin). This means that you need to regularly consume foods that are rich in B vitamins by eating a balanced diet. Good sources of B complex vitamins include dairy products, nuts and meat. In some cases, taking vitamin B complex tablets might be a good way to hit your daily RDA.

If you’re wondering ‘how much vitamin B complex should I take daily’, the answer is: it depends. The vitamin B complex RDA (recommended dietary allowance) varies by vitamin. This article covers the vitamin B complex recommended daily amount for each B vitamin.

READ ALSO: 9 Great Vitamin B Complex Food Sources

 

Thiamine (Vitamin B1)

The vitamin B complex daily dose of B1 is as follows:

Infants

  • 0-6 months – 0.2mg/daily
  • 7-12 months – 0.3mg/daily

Children

  • 1-3 years – 0.5mg/daily
  • 4-8 years – 0.6mg/daily
  • Boys 9-13 years – 0.9mg/daily
  • Girls 9-13 years – 0.9mg/daily

Adolescents and adults

  • Men 14 years and older – 1.2mg/daily
  • Females 14-18 years – 1mg/daily
  • Women 18 years and older – 1.1mg/daily
  • Pregnant women – 1.4mg/daily
  • Breastfeeding women – 1.5mg/daily

 

Riboflavin (Vitamin B2)

The vitamin B complex dosage per day for riboflavin is as follows:

Infants

  • 0-6 months – 0.3mg/daily
  • 7-12 months – 0.4mg/daily

Children

  • 1-3 years – 0.5mg/daily
  • 4-8 years – 0.6mg/daily
  • 9-13 years – 0.9mg/daily

Adolescents and adults

  • Males 14-18 years – 1.3mg/daily
  • Females 14-18 years – 1mg/daily
  • Men 18 years and over – 1.3mg/daily
  • Women 18 years and over – 1.1mg/daily
  • Pregnant women – 1.4mg/daily
  • Breastfeeding women – 1.6mg/daily

 

Niacin (Vitamin B3)

For niacin, the recommended daily vitamin B complex dosage is as follows:

Infants

  • 0-6 months – 2mg/daily
  • 7-12 months – 4mg/daily

Children

  • 1-3 years – 6mg/daily
  • 4-8 years – 8mg/daily
  • 9-13 years – 12mg/daily

Adolescents and adults

  • Males 14-18 years – 16mg/daily
  • Females 14-18 years – 14mg/daily
  • Men 18 years and over – 16mg/daily
  • Women 18 years and over – 14mg/daily
  • Pregnant women – 18mg/daily
  • Breastfeeding women – 17mg/daily

 

Pantothenic Acid (Vitamin B5)

The vitamin B5 (pantothenic acid) recommended daily intake is as follows:

Infants

  • 0-6 months – 1.7mg/daily
  • 7-12 months – 1.8mg/daily

Children

  • 1-3 years – 2mg/daily
  • 4-8 years – 3mg/daily
  • 9-13 years – 4mg/daily

Adolescents and adults

  • Men and women 14 years and older – 5mg/daily
  • Pregnant women – 6mg/daily
  • Breastfeeding women – 7mg/daily

 

Pyridoxine (Vitamin B6)

The vitamin B complex dosage for pyridoxine (vitamin B6) is as follows:

Infants

  • 0-6 months – 0.1mg/daily
  • 7-12 months – 0.3mg/daily

Children

  • 1-3 years – 0.5mg/daily
  • 4-8 years – 0.6mg/daily
  • 9-13 years – 1mg/daily

Adolescents and adults

  • Males 14-50 years – 1.3mg/daily
  • Females 14-18 years – 1.2mg/daily
  • Men 50 years and over – 1.7mg/daily
  • Women 50 years and over – 1.5mg/daily
  • Pregnant women – 1.9mg/daily
  • Breastfeeding women – 2mg/daily

 

Biotin (Vitamin B7)

There is no recommended vitamin B complex dosage for biotin because it’s made in the body and there’s little in food. However, an adequate intake (AI) is established for biotin. The AI is similar to the vitamin B complex RDA. AI is generally set when there’s not enough evidence to establish a recommended daily allowance/intake.

The adequate intake (AI) of biotin:

Infants

  • 0-12 months – 7mcg/daily

Children

  • 1-3 years – 8mcg/daily
  • 4-8 years – 12mcg/daily
  • 9-13 years – 20mcg/daily

Adults and adolescents

  • Males and females 14-18 years – 25mcg/daily
  • Men and women over 18 and pregnant women – 30mcg/daily
  • Breastfeeding women – 35mcg/daily

 

Folate and Folic Acid (Vitamin B9)

vitamin B complex RDA

Your body converts folate into folic acid, which has many health benefits. Supplements contain folic acid directly so they are better absorbed by the body than the folate contained in food. The recommended folate intake from food is also known as the dietary folate equivalent (DFE).

The vitamin B complex dosage for folate is listed below. Amounts expressed in DFE indicate that folate needs to be consumed from food. Amounts expressed in mcg indicate that folate needs to be taken from supplements.

Infants (there is no RDA for infants)

  • 0-6 months – 65mcg/daily
  • 7-12 months – 80mcg/daily

Children (RDA)

  • 1-3 years – 150mcg/daily
  • 4-8 years – 200mcg/daily
  • 9-13 years – 300mcg/daily

Adolescents and adults

  • Males and females 14-18 years – 400mcg/daily
  • Pregnant females 14-18 years – 600mcg/daily
  • Breastfeeding females 14-18 years – 500mcg/daily
  • Men and women 18 years and over – 400mcg DFE/daily
  • Pregnant women – 600mcg DFE/daily
  • Breastfeeding women – 500mcg DFE/daily
  • Women capable of becoming pregnant – 400mcg/daily
  • Pregnant women – 600mcg/daily
  • Pregnant women with a previous history of neural tube defects – 4mg/daily

 

Cobalamin (Vitamin B12)

The recommended daily vitamin B complex dosage for vitamin B-12 (cobalamin) is as follows:

Infants (AI)

  • 0-6 months – 0.4mcg/daily
  • 7-12 months – 0.5mcg/daily

Children

  • 1-3 years – 0.9mcg/daily
  • 4-8 years – 1.2mcg/daily
  • 9-13 years – 1.8mcg/daily

Adolescents and adults

  • Males and females over the age of 14 – 2.4mcg/daily
  • Pregnant teens and women – 2.6mcg/daily
  • Breastfeeding teens and women – 2.8mcg/daily

 

Vitamin B Deficiency

vitamin B complex dosage per day

Being deficient in the vitamin B complex can result in a variety of health problems, some of which can be serious. If you are deficient in one of the B vitamins, you are likely to be deficient in others as well. That’s why getting your daily vitamin B complex dosage right is important.

While vitamin B complex deficiency is rare in the Western world, some people may be more likely to develop it. These include:

Pregnancy and breastfeeding can also make you deficient in B vitamins. A vegan diet can make it harder to meet vitamin B complex dosage, in particular vitamin B12.

If you’re not getting your vitamin B complex dosage right, health problems can include:

  • Wernicke/Korsakoff syndrome – brain damage, which can be permanent and fatal if left untreated (thiamine deficiency)
  • Angular cheilitis – swollen, scaly, dry lips that are cracked in the corners (vitamin B6 and/or B2 deficiency)
  • Glossitis – swollen, glossy tongue (vitamin B6 or B12 deficiency)
  • Anaemia – iron deficiency leading to fatigue, breathlessness, palpitations, which can lead to dementia if left untreated (more common with folic acid or vitamin B12 deficiency)
  • Numbness and burning in the hands and feet (vitamin B5 deficiency)
  • Pellagra – rough patchy skin, bright red tongue, digestive issues and brain damage if left untreated (niacin deficiency)
  • Changes to the skin, eyes and hair
  • Problems with the circulatory system (more common with thiamine deficiency)
  • Weight loss
  • Depression
  • Fatigue
  • Birth defects, such as spina bifida (folic acid deficiency)

 

Vitamin B Complex Overdose

If you thought that increasing your vitamin B complex dosage is dangerous, think again. Unlike other vitamins and minerals, there is no evidence that taking too much B complex is harmful. It’s impossible to overdose on B vitamins through food intake, but it can happen when taking supplements. Taking too much can cause side effects in some cases.

Taking too much vitamin B3 (niacin) can result in a niacin flush, which is a hot burning feeling in the face. While this isn’t harmful, it can be quite uncomfortable. If you take too much vitamin B3 for a long time (especially extended-release niacin), this can lead to liver damage.

vitamin b dosage

A high dose of vitamin B6 can result in peripheral neuropathy. This is the loss of feeling in the arms and legs and muscle weakness, which can result in from nerve damage. It’s usually reversible but can result in permanent damage if the overdose is continued over the course of several months.

Taking too much folic acid isn’t harmful per se, but it can mask the symptoms of vitamin B12 anaemia. That’s because both folic acid and vitamin B12 can affect the same amino acids. If vitamin B12 anaemia is left untreated for too long, it can result in permanent nerve damage.

Always discuss with your GP before introducing a vitamin B complex supplement to your diet for more accurate medical advice. Most supplements only provide enough B vitamins to hit your recommended daily vitamin B complex dosage. However, taking a food-first approach to nutrition is still an excellent (if not better) way of meeting your RDA.