Vitamin B

B vitamins are a family of vitamins that work together yet also have very individual roles. Many of them are required for energy metabolism (release of energy from the food we eat), nervous system function (the way our brain and... Read more

B vitamins are a family of vitamins that work together yet also have very individual roles. Many of them are required for energy metabolism (release of energy from the food we eat), nervous system function (the way our brain and nerves work) and have a role in building red blood cells; and some are variously involved with hormone balance, heart function, skin or eye health.

Different B vitamins are found in different foods too – for example, while many B vitamins can be obtained by eating a variety of plant foods, vitamin B12 is only found in significant amounts in animal foods. Read on for more information on each of the B vitamins and where we can find them.

Primary functions of B vitamins

  • Energy metabolism – this means they have individual roles in the conversion of carbohydrates from our food to energy in our cells: vitamins B1, B2, B3, B5, B6 and B12.
  • Nervous system function – how our brain and nerves communicate: vitamins B1, B2, B3, B6 and B12.
  • Normal psychological function – how we feel and our mood: vitamins B1, B3, folate, B6, B12.
  • Building and maintaining the health of the red blood cells that carry oxygen around our body for energy: vitamins B2, B6, B12 and folate.
  • Supporting a healthy immune system: vitamins B6, B12 and folate.
  • Homocysteine metabolism. Homocysteine is a substance that is associated with heart disease when allowed to build up to high levels in the body – B vitamins are needed to help to control its levels. Vitamins B6, B12 and folate.
  • Healthy heart function: vitamin B1.
  • Normal skin and vision: vitamin B2.
  • Hormonal balance and regulating hormone activity: vitamins B5 and B6.

How much do we need?

As each B vitamin is a separate substance and has an individual role, they are all needed in different amounts. Here are the EU nutrient reference values for each of the primary B vitamins. Nutrient reference values refer to the amount needed to ensure that the needs of nearly all the population (97.5%) are being met.




Vitamin B1 (Thiamine)

1.1 mg

Vitamin B2 (Riboflavin)

1.4 mg

Vitamin B3 (Niacin)

16 mg

Vitamin B5 (Pantothenic Acid)

6 mg

Vitamin B6

1.4 mg

Vitamin B12

2.5 µg (micrograms)


200 µg (micrograms)


You may notice that these levels are much lower than you’ll see in some B vitamin supplements. There are a few reasons for this. Firstly, the NRVs are really minimum levels that our bodies need to prevent deficiency, and not necessarily optimal levels that we could be getting in our diet. Secondly, B vitamins are water-soluble, meaning that the body easily gets rid of what it doesn’t need; they don’t build up in the body to the same extent as the fat-soluble vitamins such as vitamin A and D. And thirdly, the absorption rate of a B vitamin in a supplement may not be as good as absorption from a food, meaning that we may need to take more in order to absorb enough.

Food sources of B vitamins

Here are some of the best foods you can eat as natural sources of B vitamins.

Vitamin B1: sesame seeds, flax seeds, macadamia nuts, lentils, beans, pork and tuna.

Vitamin B2: liver, kidney, eggs, shiitake mushrooms, goat’s and feta cheese, almonds.

Vitamin B3: anchovies, tuna, wild salmon, liver, peanuts, shiitake mushrooms, chicken, sesame seeds.

Vitamin B5: shiitake mushrooms, liver, sunflower seeds, wild salmon, trout, eggs.

Vitamin B6: potatoes with skin, peppers, beef, pistachio nuts, walnuts, sunflower seeds.

Vitamin B12: liver, kidneys, clams, oysters, mackerel, herring, most other fish and meats, eggs.

Folate: liver, beans (most types), lentils and split peas, sunflower seeds, spinach, asparagus.

This list shows that eating a wide range of whole foods, including fish, seeds and nuts, organ meats and other meats, eggs is the best way to make sure we are getting as much as we can in the way of B vitamins.

Forms and bioavailability

For some B vitamins, the ‘standard’ supplement form may not be the same as the form of the vitamin that’s used by our body. One example is folate: a form called folic acid is often used in supplements and fortified foods, but this is not the same as naturally occurring ‘food folate’. The body can convert the supplement forms such as folic acid to the more useful forms, but this conversion may not work very well in some individuals. For this reason, some B vitamin supplements now contain the more useful (sometimes called ‘activated’ or ‘body-ready’ forms) of the B vitamins, which may be better for some people.

The ones that stand out are:

Vitamin B6: the standard form is pyridoxine hydrochloride, but the active form is pyridoxal-5-phosphate.

Folate: as above, the standard form to use in supplements is folic acid, but this is a synthetic form of folate that some people do not metabolise very well. Better forms are folinic acid (which is rare in supplements) or methylfolate (full name 5-methyl tetrahydrofolate).

Vitamin B12: the most common form to use in supplements is cyanocobalamin, but again this is a synthetic form of vitamin B12. The natural, active form found in some supplements is methylcobalamin, and this may be easier for the body to use.

This means that if you are looking for the best possible B vitamin supplement, or one that contains the most natural forms of B vitamins, then looking for these forms noted above may be beneficial. However, this doesn’t mean that the ‘standard’ B vitamins or B complex supplements will not benefit you, or that it’s necessary for everyone to choose the active forms.

Dosages: Lifestyle Labs’ recommendations

Dosages of vitamins B1, B2, B3, B5 and B6 in B complex or multivitamin supplements can vary from as little as the nutrient reference values (NRVs, as given above) to around 50mg or up to 100mg each. A product containing up to 50mg of each is considered a moderate-dose supplement that is suitable for most people on a long-term basis. A B complex supplement containing 100mg of each of these B vitamins is generally considered a high-dose product that may be recommended for someone who has greater need – for example someone who has a very busy lifestyle. Each of these B vitamins can also be found as individual supplements at higher doses, and are often recommended by practitioners for specific purposes: dosages can be up to 500mg for vitamins B1, B3 and B5, and usually not more than 200mg for vitamins B2 and B6.

Folate or folic acid tend to be found in supplements at between 200 and 800 µg (micrograms) per daily dose, and it’s rare that someone would be recommended to take more than that.

Vitamin B12 can be found in multi or B complex supplements at anywhere between the NRV and 1000 µg (micrograms). Individual B12 supplements can contain as much as 5000 µg, and these may be recommended for people who have a known deficiency in this vitamin.

Children: B vitamins are found in children’s multivitamin and mineral supplements, but rarely found as individual supplements or B vitamin complexes. Most supplements for children contain levels close to the NRV, with some containing up to around 30mg (for B3, B5 and B6). Practitioners may advise higher doses or individual B vitamin supplements for children.


If you are taking any medications or have any medical condition, please consult your healthcare practitioner before taking B vitamins.  

Because they are water-soluble and can easily be excreted by the body, B vitamins are generally considered safe supplements for most people. However, there are a few caveats to this.

  • Taking high-dose folate on its own may ‘mask’ a vitamin B12 deficiency.
  • Vitamin B12 stores can build up in the body and, although there are no known harmful effects of having high levels, it is advisable to get your doctor to do a regular vitamin B12 test if you are taking high-dose B12 because of a deficiency.
  • High doses of vitamin B6 or even long-term usage of dosages as low as 10mg may lead to mild tingling and numbness in the extremities, which goes away when you stop taking it.
  • High doses of individual B vitamins may not suit everyone, especially on a long-term basis. If you want to take a high dose of one or more B vitamins (i.e. over the amount found in a B complex supplement) then it’s advisable to seek the advice of a practitioner to make sure that this is right for you.
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