Learn all about B-Complex
What is B-Complex?
Boost energy & sharpen focus with B-complex vitamins. Supports nerve function & helps turn food into fuel. Feel the difference!
Benefits of B-Complex
"B vitamins are fundamental for how our cells make energy. While severe deficiencies are rarer now due to fortified foods, having less-than-ideal levels is common, especially in older adults (less B12 absorption), heavy drinkers, and those under chronic stress. B vitamins work as a team – a shortage in one often affects others. That's why a balanced B-complex is often better than taking single B vitamins. If you have unexplained fatigue, mood issues, or brain fog, checking your B vitamin status might help."
- Dr. Sarah Gibson, Consultant Dietitian and Clinical Nutritionist at University College London Hospitals NHS Foundation Trust (source)
How to use B-Complex
Dosage
Usually provides 100% of the UK recommended daily amount (RNI) for each B vitamin. Higher strength versions exist. Doses for specific health issues vary.
Timing
Best taken morning or early afternoon, as some B vitamins might boost energy. Can be taken with or without food.
Notes
B2 (Riboflavin) makes urine bright yellow (this is harmless). 'Active' forms (like methylcobalamin for B12, methylfolate for B9) might be better absorbed by some people, especially those with certain common gene variations. 'Time-release' types release vitamins slowly.
Who should take B-Complex?
- People needing more nutrients due to stress, illness, or high physical activity
- Older adults (who may absorb less B12)
- Those on restricted diets (like vegetarian/vegan, which lack B12) or low-calorie diets
- People taking certain medications that can lower B vitamin levels (e.g., some acid reflux drugs, metformin for diabetes, birth control pills)
How does B-Complex work?
B vitamins act as essential helpers ('coenzymes') for countless body processes. B1, B2, B3, and B5 are crucial for the main energy-making processes in our cells, turning carbs, fats, and proteins into fuel ('ATP'). B6 helps with building proteins and making brain chemical messengers ('neurotransmitters'), affecting mood and thinking. B9 (Folate) and B12 work together to make DNA, form red blood cells, and manage homocysteine levels (important for heart and nerve health). B7 helps make and use fats, sugars, and proteins. Together, B vitamins also support the body's defences (immune and antioxidant systems) and hormone balance. Because most are water-soluble, we usually need to get them regularly as the body doesn't store much (except B12, stored in the liver).
Frequently asked questions
Natural sources of B-Complex
B vitamins are in many foods, but amounts vary. Whole grains have B1, B2, B3, B6 (but processing removes them, so fortified grains are important). Meat, poultry, fish, eggs, and dairy provide all B vitamins; liver is very rich. B12 is found almost only in animal foods, so vegans/vegetarians need supplements or fortified foods. Leafy greens, beans, and nuts supply good amounts of folate and B6. Nutritional yeast is packed with B vitamins. Cooking and processing can reduce B vitamins as they can be damaged by heat or lost in water. How well we absorb them ('bioavailability') can be affected by other food components ('anti-nutrients'), alcohol, and certain drugs.
Potential side effects & risks
Warnings
Check with a doctor before taking high doses if you have kidney or liver disease. People with cancer history should discuss B vitamin use with their cancer doctor ('oncologist'). Pregnant women need specific prenatal vitamins with the right amount of folate.
Side effects
Generally safe at usual doses. Too much niacin can cause skin flushing/itching (especially non-'flush-free' types). Very high B6 doses (over 200mg daily long-term) can cause nerve damage ('peripheral neuropathy'). Bright yellow urine from B2 is normal and harmless.
Interactions
May affect how some drugs work, including certain seizure medications, antibiotics, and chemotherapy drugs. High-dose niacin can interact with cholesterol drugs (statins) and blood pressure meds. B6 might reduce the effect of levodopa (for Parkinson's) if not taken with carbidopa. Check with your doctor.