A lot, as it turns out. From folic acid to riboflavin and biotin, here’s what you need to know about the B vitamins. For healthy skin, efficient fat burning and more energy, read on…

Vitamin D  has been hogging the limelight of late, leaving other vital vits in the shade. Go back in the vitamin alphabet slightly and you’ll find the complex and multifaceted vitamin B quietly doing its thing to keep your nervous system in check, red blood cells ticking over and helping you to release energy from the food you eat. No biggie then.

In a somewhat niche study, researchers from the University of York recently identified that the high levels of vitamin B12 present in Marmite could help to boost brainpower and slow the onset of neurological disorders such as dementia and Alzheimer's, owing to the love/hate spread’s impact in terms of increasing levels of GABA neurotransmitters in the brain. Luckily for Marmite haters, yeasty unctions aren’t the only way to get your daily dose of B vitamins, particularly since there are so many branches of the B vitamin family.

From nervous system regulating thiamin in peas to skin enhancing niacin in meat, fish and eggs , the B vitamins are squirreled away in many a food source, but as the majority can’t be stored in the body, it’s key to get your fill in your diet every day. For some, such as women hoping to conceive  or in the  early stages of pregnancy , particular forms of vitamin B are essential in higher quantities, while for others dietary restrictions may increase the need for supplementation (see more on what to eat when pregnant here ). We put our vitamin B queries to dietitian and  British Dietetic Association  spokesperson Rebecca McManamon :

How many B vitamins are there and what are their benefits?

“There are eight B vitamins - thiamin (B1), riboflavin (B2), niacin (B3), pantothenic acid, B6, biotin (B7), folate and vitamin B12. They are all important, but some have more pivotal roles to certain people or health conditions, and some we need more of. For example, it isn't thought you need much biotin, but there has been recent controversy about whether there is a vitamin B17 (laetrile), found in apricot kernels. This is not a vitamin, and there is no evidence that it prevents cancer, plus foods such as apricot kernels can be harmful due to arsenic, so I wouldn't recommend them.”

Apricot kernels aside, here’s the NHS breakdown of where the various B vitamins can be sourced, and what they’ll do for you:

Thiamin (B1)

What it does: Breaks down and helps to release energy from food, helps to maintain a healthy nervous system.

Find it in: Fresh and dried fruit, eggs, wholegrain bread, liver, fortified breakfast cereals and uh...peas.

Riboflavin (B2)

What it does: Helps the body to release energy from food, assists in maintenance of healthy skin, eyes and nervous system.

Find it in: Rice, eggs, milk and fortified breakfast cereals.Store these foods out of direct sunlight as UV light can damage riboflavin.

Niacin (B3)

What it does: Helps to maintain healthy skin and nervous system and releases energy from food.

Where you’ll find it: Eggs, meat, milk, fish and wheat flour.

N.b: don’t take niacin supplements (or any supplements really) unless medically advised. Too much niacin over a prolonged amount of time can cause liver damage, plus skin flushing in the short term.

Pantothenic acid (B5)

What it does: Assists in the release of energy from food, helps riboflavin to function efficiently and keeps red blood cells healthy.

Where you’ll find it: Almost all meat and vegetables apparently, so it’s an easy hit. Tuck into beef, broccoli, eggs, wholegrains, chicken, potatoes and tomato. The NHS also highlights kidney and porridge as rich sources. Know which one of the two we prefer.

Vitamin B6

What it does: Helps the body to use and store protein and carbohydrates in food, crucial in the formation of haemoglobin found in red blood cells which carries oxygen around the body.

Where you’ll find it: B6 is abundant in the buffet of life. Choose pork, poultry, fish, eggs, milk, potatoes, wholegrains vegetables, soya beans, peanuts and fortified breakfast cereals.

Biotin (B7)

What it does: Helps the body to break down fat.

Where you’ll find it: In many foods at very low levels, and living in your bowel.

Folic Acid (folate in its natural form)

What it does: The one that most of us have heard of, folic acid helps the body to form healthy red blood cells and reduces the risk of central neural tube defects such as spina bifida in unborn babies.

Where you’ll find it: Folate can be found in small amounts in broccoli, spinach, asparagus, peas, chickpeas and fortified breakfast cereals. If you’re desperate, it’s also lurking in brussels sprouts and liver, and pregnant women should avoid the latter.

Vitamin B12

What it does: Another well known B vit, vitamin B12 keeps your nervous system in good working order, helps the body to form red blood cells, releases energy from food and is assists the body to use folic acid.

Where you’ll find it: Meat, salmon, cod, milk, cheese, eggs and fortified cereals.

Might certain people need vitamin B more than others?

“Any woman even thinking of having a baby should take 400 micrograms of folic acid a day, as it needs to be taken at least three months before conceiving, and throughout the first trimester.”

“Women with a BMI over 30, diabetes, coeliac disease or a family history of neural tube defects should consult with a registered dietitian or doctor before they up their intake, but they are usually recommended a prescription of 5 mg.”

Vegetarians , vegans  and people taking the diabetes medication Metformin are at higher risk of B12 deficiency, so therefore may need to supplement.”

“Alcohol also depletes and interferes with the way our body deals with thiamin - any one drinking over the recommended alcohol limits and anyone with alcohol addiction needs higher doses of thiamin.”

What are some rich natural sources of vitamin B?

“Speaking generally, vegetables (especially green), fruit, flour, fortified breakfast cereals and dairy products contain the B vitamins in different proportions. B12 is predominantly found in dairy and meats, which is why vegans usually need supplementation.”

What are the symptoms of vitamin B deficiency?

“Tiredness and fatigue may occur. Nerve damage and anaemia can be linked too.”

How can you treat vitamin B deficiency?

"It depends on the reason why a person is deficient, for example, people with an alcohol dependency couldn't consume enough thiamin to ensure that they won't become deficient so would need to take tablets.”

“Someone with a folate deficiency without any other health conditions may be lacking because they don't eat vegetables often enough, so as long as the deficiency isn’t severe, the best course of treatment could be dietary change. I would only advise supplementation if you are at risk or recommended to do so by a healthcare professional.”

Is there such a thing as too much vitamin B?

“For some B vitamins such as B12, there is no harmful upper level, but for folate, taking too much can hide a deficiency of vitamin B12, while excessive B6 supplementation can cause nerve damage (peripheral neuropathy).”

“As with most vitamins, I would advise people not to take more than one supplement, not to exceed the dose advised, and to seek guidance from a registered dietitian or doctor if they need to take vitamin B supplements.”

If you do need to supplement your diet and a few spoonfuls of Marmite don’t appeal (*eyes water*), there are a few new nifty options on the market to boost everything from concentration to digestion:

The Nue Co Energy Food , £55

Not your average protein powder, Energy Food combines brown rice protein with prebiotic  inulin and maca to promote healthy a metabolism and keep blood sugar levels on an even keel. High in magnesium , vitamin B12 and bioavailable (i.e, useful to the body) calcium , it’s a boost for brain, muscles, bones and red blood cells. Stir 5g into milk, yogurt or a smoothie every day.

BetterYou B12 Boost Oral Spray , £11.95

If you know you’re deficient in vitamin B12, this spray on supplement in an intriguing option, as research by Cardiff University found that B12 uptake was improved if sprayed onto the inner cheek. Only 1 per cent of vitamin B12 is retained from diet alone, but according to researchers B12 is readily and quickly absorbed through the soft tissue of the mouth, with the proximity of the vascular system near the cheek playing a part. Founder and MD of BetterYou Andrew Thomas explains:

“Our daily required intake for health maintenance is relatively small, however few foods catch rich sources (red meats and offal are major sources) and more restricted diets omit these. In addition, B12 is a very difficult vitamin to absorb and our digestive efficiency is reducing rapidly.”

“Supplementation is becoming more of a necessity for us and using a spray in the mouth bypasses the digestive system, ensuring optimal absorption.”

Rebecca doesn’t see B12 sprays as any more effective as tablets, but it’s worth a squirt if you’d like to try something alternative to traditional supplements.

Follow Rebecca on Twitter  @Rhumfrey , the BDA  @BrDieteticAssoc  and Anna  @AnnaMaryHunter