What is B-complex good for?
B-complex is the collective name generally given to the full group of B vitamins, each playing a vital role in our body's ability to function, ranging from our cardiovascular health, cell metabolism, cholesterol levels, nervous system and immune system, right through to our mental health and hormone balance.
In addition to that, many B vitamins also work together, enhancing each other's activity and absorption, as well as the activity and absorption of many other nutrients.
As we are unable to synthesize B vitamins in their required amounts ourselves, we must obtain them through our diet. Animal-sourced foods such as meat, fish, eggs and dairy are particularly rich in B vitamins, although they can also be found in many vegetables too.

Main B-complex ingredients
The average vitamin B-complex supplement will generally include the following eight vitamins:
- Vitamin B1 (Thiamin): Essential for the healthy development and function of many organs, including our heart and brain, as well as our gut health, muscle function and blood sugar regulation.
- Vitamin B2 (Riboflavin): Riboflavin is directly involved in cell metabolism and in the production of energy, as well as playing an important role in antioxidant activity.
- Vitamin B3 (Niacin): We need niacin for ensuring correct function of our cardiovascular health, hormone balance and metabolism, as well as dealing with inflammation and regulating cholesterol. In fact, niacin is often prescribed separately for people who have issues with cholesterol levels.
- Vitamin B5 (Pantothenic acid): Vitamin B5 is essential for the healthy development and function of our cardiovascular system, nervous system and brain, as well as for hormone balance and metabolism.
- Vitamin B6 (Pyridoxine): This vitamin plays a vital role in our immune system, as well as in the production of red blood cells, which are essential for transporting oxygen throughout the body. It is also vital for our nervous system and for our mental health. In fact, a deficiency in vitamin B6 has been associated with an increased risk of depression.
- Vitamin B7 (Biotin): Biotin is essential for the function of our nervous system, as well as playing key roles in our metabolism and enzyme function. It has also been associated with promoting skin health and hair health, and reducing the risk of developing diabetes.
- Vitamin B9 (Folic acid): Folic acid, also known as folate, plays a crucial role in cell metabolism, cardiovascular health, mental health, and in the formation of DNA. It also forms a critical part of the development of the fetus during pregnancy, as well as healthy growth during infancy, childhood and adolescence.
- Vitamin B12 (Cobalamin): Vitamin B12 is required for a healthy heart, healthy bones, and a healthy brain. Sadly, vitamin B12 deficiency is fairly common, and has been associated with many health conditions, including depression.
Other ingredients included in B-complex
In addition to these, most formulations of B-complex also include inositol, which is sometimes referred to as vitamin B8. Technically, inositol is not a vitamin, as it has been discovered that the human body can synthesize inositol by itself in the amounts it requires, however it performs many functions similar to B vitamins, and inositol supplementation has been demonstrated to have multiple benefits, so it makes perfect sense to include it in B-complex formulations.
You might also encounter choline in the ingredient list, which has been referred to in the past as vitamin B4, and is similarly involved in metabolism, nervous system, brain health, cardiovascular health and muscle function.
B vitamin deficiency
While most people may typically only require supplementing one or two specific B vitamins, such as vitamin B12 for example, anyone who follows a vegetarian or vegan diet is at a higher risk of developing an overall vitamin B deficiency, as are older adults, or people who suffer from any health condition that could impair vitamin absorption.
When should I take my B-complex?
Many B vitamins are known for their energy-boosting properties, while some specific B vitamins, such as vitamin B6, are known to potentially interfere with sleep quality. This, combined with their overall function in cell metabolism, makes them best taken early in the day.
B vitamins are also water-soluble, meaning they do not need to be taken with food in order to be properly absorbed, and in fact most B vitamins, if not all, are best absorbed when taken without food. So, with all this in mind, taking your vitamin B-complex first thing in the morning, before breakfast, is the ideal moment.
What does B-complex combine well with?
B-complex with magnesium, green tea extract and rhodiola extract
One study that combined vitamin B-complex with magnesium, green tea and rhodiola extract observed an increase in spectral theta brain activity, resulting in an increased capacity to perform tasks that require high levels of attention during stressful moments.
B-complex with omega-3 fatty acids
Omega-3 fatty acids are known to combine well with many B vitamins in several ways. Studies have found that when B vitamins were present in abundance before consuming fish oil for example, participants exhibited an improved cognitive performance and increased blood flow to the brain once the fish oil supplement was taken.
Other studies have concluded that both omega-3 fatty acids and B vitamins both need to be present in certain amounts for optimal brain function. Another rich source of omega-3 is Krill oil.
B-complex with garlic extract and L-arginine, for cardiovascular health
It has also been found that when vitamins B6, B9 and B12 are taken in combination with aged garlic extract and L-arginine, there is a significant reduction in the progression of atherosclerosis and related cardiovascular complications.
What should I avoid taking my B-complex with?
Avoid taking B-complex with red yeast rice extract
It is advised to avoid taking vitamin B-complex supplements at the same time as red yeast rice extract, as both niacin (vitamin B3) and red yeast rice extract are known to affect how muscles work, and could have potential adverse effects on muscle function when combined, including the heart muscle.
To avoid this situation, make sure you take these supplements at least three hours apart.
Avoid taking B-complex with selenium
Selenium is an element that is known to interact with niacin (vitamin B3), so you would be advised to avoid taking your vitamin B-complex supplement at the same time as any selenium supplement to reduce the interaction.
Avoid taking B-complex with vitamin E
Likewise, vitamin E is also known to interact negatively with niacin (vitamin B3), so make sure to take your B-complex supplement several hours apart from any supplemental dose of vitamin E to avoid this.
Avoid taking B-complex with vitamin C
Supplementation of vitamin C is known to have a negative effect on the amount of available vitamin B12 in the body. Furthermore, it also hinders your body's ability to absorb vitamin B12 from food. Because of this, it is recommended to take any vitamin C supplement and B-complex supplement separately, at least two hours apart, in order to avoid this interaction.
Avoid taking B-complex with spirulina
The same applies to spirulina. Specifically, the vitamin B12 "analogues" that can be found in spirulina actually inhibit absorption of the real vitamin B12 that is found in your B-complex supplement.
What are natural sources of B-complex?
If you are interested in achieving your daily B-complex intake through your diet, rich sources of B-complex include:
- Beef liver
- Beef
- Pork
- Salmon
- Trout
- Mussels
- Clams
- Oysters
- Chicken
- Turkey
- Eggs
- Milk
- Cheese
- Yoghurt
- Seeds
- Spinach
B-Complex data sources & further reading
- https://www.healthline.com/nutrition/best-time-to-take-vitamins
- https://www.webmd.com/drugs/2/drug-10619-280/super-b-complex-oral/multivitamins-w-iron-includes-prenatal-vitamins-oral/details
- https://www.medicalnewstoday.com/articles/319556
- https://www.webmd.com/diet/health-benefits-b-complex
- https://www.mindbodygreen.com/articles/best-time-to-take-vitamin-b-complex
- https://www.healthline.com/health/food-nutrition/vitamin-b-complex
- https://www.medicalnewstoday.com/articles/324856
- https://www.sciencedirect.com/science/article/pii/S2475299123098141
Last updated by Asklepios on 1st February, 2025