B12 vs B Complex

B vitamins are a group of eight water-soluble vitamins that play many important roles in the body.

From helping our bodies convert food into energy, creating new blood cells, and maintaining healthy skin cells, brain cells, and other body tissues, these vitamins make sure our cells are functioning properly.

B vitamins are often found together in the same foods and most people get enough B vitamins by eating a variety of nutrient-dense foods.

Good food sources of B vitamins include:

• Meat (especially liver)
• Seafood
• Poultry
• Eggs
• Dairy products
• Legumes
• Leafy greens
• Seeds
• Fortified foods such as breakfast cereal and nutritional yeast

Some people may struggle to get enough B vitamins. Older adults, pregnant and lactating people, vegetarians and vegans, people with certain medical conditions such as celiac disease, cancer, alcoholism, and anorexia, or those taking certain medications such as proton pump inhibitors or birth control pills, are at higher risk of having low levels of B vitamins.

Those who struggle to meet their daily needs can take supplements to prevent B vitamin deficiencies.

B complex supplements contain all eight B vitamins in one pill, including vitamin B12, and are generally used by people who are low in multiple B vitamins.

You can also get supplements with just B12 alone for those people who are deficient in vitamin B12 only.

Let’s take a closer look at the B vitamins individually and why they’re so important.

B Complex Vitamins

B1 (Thiamine)

Vitamin B1 is also called thiamine. The heart, liver, kidney, and brain all contain high amounts of thiamine.

Our bodies need thiamine for: (Source)

• Converting nutrients into energy
• Creating certain neurotransmitters (brain chemicals)
• Synthesizing certain hormones

Rich food sources include pork, sunflower seeds, and wheat germ. 

B2 (Riboflavin)

Riboflavin is essential for: (Source)

• Energy production
• Helping the body break down fats, drugs, and steroid hormones

And is also an antioxidant.

Bacteria in the gut can produce small amounts of riboflavin, but not enough to meet dietary needs.

Good food sources of riboflavin include organ meats, beef, oatmeal, and mushrooms. 

B3 (Niacin)

The body converts niacin into a coenzyme called nicotinamide adenine dinucleotide (NAD). NAD is a necessary part of more than 400 different enzyme reactions in the body!

These enzymes help with: (Source)

• Converting nutrients into energy
• Communication among cells
• Creating and repairing DNA

Niacin also has antioxidant effects.

Animal-based foods such as meat, poultry, and fish are high in NAD, which the body can easily use but plant foods like nuts, legumes, and grains contain a natural form of niacin that the body doesn’t use as easily.

Foods fortified with niacin, such as cereals, contain a form of niacin that is easily used by the body too.

B5 (Pantothenic Acid)

Like other B vitamins, pantothenic acid helps your body obtain energy from food and is also involved in hormone and cholesterol production. (Source)

Good amounts of vitamin B5 can be found in beef liver, shiitake mushrooms, sunflower seeds, chicken, tuna, and avocados.

B6 (Pyridoxine)

Vitamin B6, or pyridoxine, plays a role in more than 100 enzyme reactions.

The body needs pyridoxine for: (Source)

• Amino acid metabolism
• Breaking down carbohydrates and fats
• Red blood cell production
• Brain development
• Immune function

Rich sources of vitamin B6 include organ meats, chickpeas, tuna, salmon, and potatoes. 

B7 (Biotin)

The human body needs biotin for: (Source)

• Breaking down fats, carbohydrates, and protein
• Communication among cells in the body
• Regulation of DNA

Biotin can be found in liver, yeast, eggs, salmon, cheese, pork, beef, and sunflower seeds.

You may see biotin in hair, skin, and nail supplements too. However, there is insufficient evidence to conclude that extra biotin helps with hair, skin, or nails. (Source)

B9 (Folate)

Folate is essential for: (Source)

• DNA replication
• Cell growth and proper cell division
• Formation of red and white blood cells, and proper cell division
• Metabolism of vitamins and amino acids

Folate is also extremely important for women entering into pregnancy. When a woman has adequate levels of folate both before and during pregnancy, the fetus has a lower risk of neural tube defects which are birth defects that affect the brain and spinal cord. (Source)

Because folate is largely found in leafy greens, most people can’t reach the necessary levels for pregnancy through diet alone. All women of reproductive age are recommended to take a folic acid supplement daily. Folic acid is the synthetic form of folate and is more easily used by the body. (Source)

Folate can be found in foods like leafy greens, liver, and beans or in fortified foods or supplements in the form of folic acid.

B12 (Cobalamin)

Vitamin B12 is vital for: (Source)

• Brain and neurological function
• DNA synthesis
• Creating new red blood cells
• Fat and protein metabolism

The only foods that deliver vitamin B12 are meat, eggs, poultry, dairy products, and other foods from animals. Plants don’t make B12.

Strict vegetarians and vegans are at high risk for developing a B12 deficiency if they don’t eat grains that have been fortified with the vitamin or take a vitamin supplement.

Some people don’t consume enough vitamin B12 to meet their needs, while others can’t absorb enough, no matter how much they take in. As a result, vitamin B12 deficiency is relatively common, especially among older people.

Functions Of B Complex Vitamins

Energy Production

B complex vitamins play critical roles in the body, especially when it comes to metabolizing food and converting it into energy.

An adequate supply of each B vitamin is required for our body’s energy-production system to function properly. A shortfall in any of them can negatively affect energy production, with potentially severe metabolic and health consequences. (Source)

This is why a common sign of low levels of B vitamins is fatigue, which is one of the reason this vitamin is recommended for chronic fatigue sufferers.

Research shows that both B9 and B12 deficiencies can result in overall cognitive decline and vitamin B6 deficiency is associated with reduced levels of alertness. (Source)

So will loading up on B vitamins boost energy and enhance mental performance?

Maybe, but for the most part, B vitamin supplementation has only been seen to improve energy levels and cognition in those who were deficient in these vitamins in the first place.

That being said, there is some evidence that B12 supplementation in healthy people without deficiencies can enhance alertness and concentration. (Source)

Well, what about B vitamins when it comes to physical energy?

While the B vitamins do play key roles in energy production processes, they contribute to physical energy in an indirect sort of way. Supplementing with B vitamins hasn’t been seen to provide a significant boost in energy in people without B vitamin deficiencies.

However, for people with deficiencies in B vitamins, supplementation has been seen to have positive effects on energy levels. (Source)

Brain Health

The B vitamins are also essential for optimal brain function. Aside from their roles in energy production, they are also important for DNA synthesis and repair, and creating numerous brain chemicals and signaling molecules. (Source)

Research suggests that B vitamin supplementation is associated with slowing cognitive decline. (Source)

One study investigating the effect of a high-dose B-complex and mineral supplement on healthy men found an improvement in general mental health and stress and enhanced performance on cognitive tests. (Source)

Furthermore, low blood levels of certain B vitamins, including B12, B6, and folate, have been linked to an increased risk of depression.

A study in adults with depression showed that treatment with a vitamin B complex for 60 days led to significant improvements in depression and anxiety symptoms. (Source)

Immune System Support

B vitamins also play a role in immune function. 

With the B vitamins being so integral to cell health and cell processes, it is no surprise that they are also associated with supporting immune function. Deficiencies in B vitamins have been linked to immune dysfunction and inflammatory conditions. (Source)

While research into the effect of B vitamins on immune function is still emerging, there is evidence to show that they may have beneficial effects.

One small study found that vitamin B6 supplementation had a beneficial effect on inflammatory responses in patients with rheumatoid arthritis. (Source)

Another study found that supplementation with a large dose of vitamin B6 daily for 14 days increased the immune response of critically ill patients. (Source)

However, more research into the effect of B vitamin supplementation on immune function is needed.

Conclusion: Should I Take B12 Or B Complex?

Whole foods are always the best option for including vitamins and minerals in our diet.

However, when it comes to B vitamins, some people can’t eat the necessary foods for adequate levels, and others have issues with absorption, so they have low levels no matter how much they eat. This is where supplements come in.

If you think you may be suffering from a vitamin deficiency, arrange an appointment with your doctor, who can determine whether or not you have a deficiency through blood tests.

If you do have a deficiency, your doctor may recommend taking a B Complex supplement if you’re deficient in multiple B vitamins or a B12 supplement if you are just deficient in B12.

Some people supplement with B vitamins regardless of deficiency to ensure their levels remain adequate. As B vitamins are water-soluble, any excess we consume passes through in our urine.

Human Tonik’s Supergreen Tonik contains a substantial amount of all eight B vitamins in each serving, as well as other beneficial ingredients that you won’t find in a regular multivitamin. This makes it a good choice for those looking to up their intake of B vitamins.

Lucy Brennan, ANur, BSc

Lucy Brennan is a registered associate nutritionist (ANutr) and freelance writer specializing in health, nutrition and wellness content.  She holds a BSc. (First Class Hons) in Public Health Nutrition and has over 4 years’ experience working in health communication, which is where her passion lies.

She has worked in roles with The Irish Food Board and FleishmanHillard PR, on their healthcare team, working with national and international health companies. Using this experience, Lucy now writes content in a freelance capacity. Lucy is dedicated to providing evidence-based content that is both engaging and accessible and inspires readers to make informed choices regarding their health.