Should I Take B12 or B Complex?

Updated on February 8, 2024
 by — reviewed by Jason Williams, PhD (Contributor: George Collins / Editor: Yoko Hill)
Exploring the benefits and differences between B12 and B Complex vitamins in a single concise sentence.

Should I take vitamin B12 or a vitamin B complex?

We find it pertinent to address the frequent query regarding the choice between Vitamin B12 and B complex. These complex vitamins, abundant in various healthy foods, play vital roles in our wellness.

The difference lies primarily in their composition and function.

Vitamin B12 is a single nutrient, essential for neurological health and DNA synthesis. On the other hand, B Complex encompasses multiple nutrients like niacin, contributing to overall nutrition.

Both are soluble vitamins and maintaining adequate levels is crucial for optimal health.

Understanding individual needs and how these two vitamins work in your body is vital to making informed decisions about your health.

In this article, we will cover everything you need to know about these two essential vitamins and how they can add to your life!

Understanding Vitamins B12 and B Complex

Vitamin B12 and B Complex are essential nutrients that play a crucial role in maintaining optimal health. While B12 is a single vitamin, B Complex is a blend of several B vitamins, including B12. These vitamins work synergistically to support energy metabolism and DNA/RNA synthesis.

It is important to get an adequate intake of both vitamins, either through diet or supplementation.

Vitamin B12, also known as cobalamin, is one of the eight B vitamins that make up the B Complex. It is responsible for the production of red blood cells and the maintenance of a healthy nervous system.

Unfortunately, Vitamin B12 is not found in plant sources, making it a common deficiency among plant-based individuals. It is recommended to take B12 supplements if you follow a plant-based diet.

On the other hand, B Complex consists of a group of eight B vitamins, including B12, Thiamine (B1), Riboflavin (B2), Niacin (B3), Pantothenic Acid (B5), Pyridoxine (B6), Biotin (B7), and Folate (B9). Together, these vitamins provide optimal balance and support the recommended daily amount of B vitamins.

B Complex vitamins are water soluble and cannot be stored by the body, so it is important to regularly consume foods or supplements that contain them.

The Role of Vitamin B12 in the Body

Vitamin B12, also known as cobalamin, is a crucial nutrient that plays a vital role in various bodily functions.(1) It is involved in the development, myelination, and proper functioning of the central nervous system. 

Here are some key factors about the role of B12:

  • Vital for Red Blood Cell Formation: Vitamin B12, also known as cobalamin, plays a crucial role in the production of red blood cells. These cells transport oxygen throughout the body, supporting various functions, such as energy production and immune function. A deficiency in vitamin B12 can lead to anemia, a condition characterized by fewer red blood cells than normal or insufficient hemoglobin within the red blood cells.
  • Essential for Nerve Function: The nervous system heavily relies on adequate vitamin B12 levels. This vitamin aids in producing myelin, a substance that insulates nerves and ensures fast and efficient nerve-impulse transmission. Without sufficient vitamin B12, you might experience neurological complications like numbness, tingling sensation in your hands and feet, balance problems, and cognitive difficulties.
  • Cofactor for Essential Enzymes: Vitamin B12 acts as a cofactor for two enzymes, methionine synthase and L-methylmalonyl-CoA mutase. Methionine synthase is involved in converting homocysteine into methionine, an essential amino acid important for various biological processes. L-methylmalonyl-CoA mutase is involved in the breakdown of certain fatty acids and amino acids.
  • Aids in DNA Synthesis: Vitamin B12 is a key player in cell metabolism, including DNA synthesis – the process our bodies use to create new cells. It works closely with other vitamins like folic acid (folate) and thiamine (vitamin B6) to regulate homocysteine levels – an amino acid associated with heart disease when present at high levels.

Adequate intake of vitamin B12 is necessary to support neurological function, maintain healthy red blood cells, and promote overall health and well-being. 

The Composition and Functions of B Complex Vitamins

B complex is a set of eight different vitamins.

These include:

  1. Vitamin B1 (Thiamine): Helps convert food into energy.
  2. Vitamin B2 (Riboflavin): Essential for growth and red blood cell production.
  3. Vitamin B3 (Niacin): Supports brain function and skin health.
  4. Vitamin B5 (Pantothenic acid): Involved in hormone production and breakdown of fats and carbohydrates.
  5. Vitamin B6 (Pyridoxine): Aids in amino acid metabolism, red blood cell creation, and brain development.
  6. Vitamin B7 (Biotin): Important for hair, skin, and nail health and metabolism of proteins, carbohydrates, and fats.
  7. Vitamin B9 (Folic acid): Necessary for proper brain function and mental/emotional health.
  8. Vitamin B12 (Cobalamin): Vital for neurological function, DNA production, and red blood cell development.

Each vitamin plays a unique role in maintaining health, contributing to the overall benefits of the complex.

Numerous studies have shown that these vitamins in the B Complex have several benefits,(2) including:

  • Energy Production: They help convert food into glucose, which provides energy to the body.
  • Brain Function: Vitamins like B1 are well known to support healthy brain activity.
  • Cell Metabolism: Each part of this complex plays a vital role in the metabolism of cells.

B complex vitamins can be found in various types of products and natural nootropics. It’s important to understand their benefits and functions as part of a healthy lifestyle.

Symptoms of B12 and B Complex Deficiencies

Vitamin B12 deficiency,(3) along with other B complex deficiencies, can lead to noticeable health conditions.(4)

Some common symptoms of both deficiencies include fatigue, weakness, depression, numbness, and cognitive issues.

Prolonged low levels of these vitamins may result in more serious side effects, such as pernicious anemia or neurological damage.

However, although both deficiencies share similar symptoms, like fatigue and weakness, there are some differences:

  1. High homocysteine levels: More common in vitamin B12 deficiency, this can increase the risk of heart disease.
  2. Megaloblastic Anemia: When B12 levels are low, megaloblastic anemia may develop. This condition is characterized by the production of abnormally large red blood cells that do not function properly. Symptoms may include weakness, pale skin, and shortness of breath.
  3. Neurological Problems: B12 deficiency specifically can lead to neurological damage, which may result in behavioral changes, difficulties in cognition, and problems with memory and concentration. In some cases, these neurological issues may be irreversible.
  4. Skin and Mouth Issues: Deficiencies in B vitamins can manifest as skin problems such as itchy skin rashes and cracks around the mouth. Vitamin B2 deficiency, in particular, can cause discomfort or soreness of the mouth or tongue.
  5. Muscle Weakness and Balance Issues: Inadequate levels of B Complex vitamins can weaken muscles, leading to slow reflexes and shakiness while walking. Difficulty maintaining balance and coordination may also be observed in individuals with these deficiencies.
  6. Increased Risk for Pregnant Women and Older Adults: Pregnant women with deficiencies in B9 (folate) are at an elevated risk of neural tube defects in their babies. Older adults and individuals with conditions that hinder B vitamin absorption, such as Crohn’s disease or celiac disease, are more prone to developing deficiencies due to increased requirements or reduced absorption.
  7. Diabetes: A potential side effect of prolonged B complex deficiency.

It’s crucial to identify these symptoms early on to prevent long-term health issues.

Deciding Between B12 and B Complex Supplements

B Complex and B12 are both essential for your health, but they serve different purposes. B12 is a singular vitamin, often taken separately by those on plant-based diets, to support nerve function and red blood cell formation.

On the other hand, B Complex is a combination of multiple B Vitamins, including B12, which collectively aid in energy production, metabolic function, and DNA/RNA synthesis.

It’s recommended to take them together for a synergistic effect.

However, if you’d prefer to choose one, then you need to first assess individual nutritional needs.

Lifestyle factors, or medical conditions, may influence the need for either B12 supplements or a complex supplement. 

For instance, vegetarians rarely get enough vitamin B12 into their diet as it’s primarily found in animal products.

On the other hand, people living a high-stress lifestyle would benefit from B Complex for overall support. 

Next, consider potential interactions with other medications or supplements.

Some drugs, like proton pump inhibitors used for heartburn, can affect the absorption of vitamin B12 supplements.

Lastly, understand when a combination supplement might be beneficial. There are many vital vitamins needed to support healthy cognitive function, and a more well-rounded approach may be better for you. 

Conclusion: Should I Take B12 or B Complex Supplements?

Choosing between B12 and B Complex supplements ultimately boils down to your individual health needs. If your diet lacks vitamin B12, a specific supplement can help bridge the gap. 

However, if you’re experiencing symptoms of multiple B vitamin deficiencies, a comprehensive B complex supplement might be the better choice.

It’s crucial to consult with a healthcare professional before starting any new supplement regimen to ensure it aligns with your unique health profile.

Taking steps towards improved health is commendable.

Don’t let confusion deter you from making informed decisions about your well-being.


Sources, Studies, and Scientific Research
  1. Smith, A David et al. “Vitamin B12.” Advances in food and nutrition research vol. 83 (2018): 215-279. doi:10.1016/bs.afnr.2017.11.005 
  2. Hanna, Mary et al. “B Vitamins: Functions and Uses in Medicine.” The Permanente journal vol. 26,2 (2022): 89-97. doi:10.7812/TPP/21.204 
  3. Ankar, Alex. and Anil Kumar. “Vitamin B12 Deficiency.” StatPearls, StatPearls Publishing, 22 October 2022. 
  4. Ali, Mennatallah A et al. “Dietary Vitamin B Complex: Orchestration in Human Nutrition throughout Life with Sex Differences.” Nutrients vol. 14,19 3940. 22 Sep. 2022, doi:10.3390/nu14193940 
chevron-down