Written by Elliot Reimers
Elliot received his B.Sc. in Biology/Biochemistry from the University of Minnesota; he is thoroughly passionate and educated about the science behind human physiology, nutrition, & dietary supplementation. He is a published author on many mainstream fitness/health media sites.
B vitamins have a multitude of actions throughout the human body and are associated with virtually every metabolic reaction. As such, B vitamins are essential for a myriad of physiological processes, including proper synthesis of neurotransmitters, manufacturing energy, cellular respiration, and maintaining healthy DNA.
In addition, longitudinal research studies admonish that being deficient in certain B vitamins may accelerate brain tissue degeneration and inhibit cognitive function, demonstrating just how imperative these vitamins are for brain health.
Chances are you already know those tidbits of information, but did you know that modest amounts of niacin may help prevent/reverse dementia? Or that thiamine deficiency can drastically increase your risk of type-2 diabetes?
Let’s take a closer look at how B vitamins function, their research-backed benefits, the proper ways to supplement with them, and any possible side effects/safety issues you should be aware of.
Classifying B Vitamins
B vitamins comprise a group of micronutrients, which are substances that your body requires in relatively small quantities to subsist. For example, the recommended daily allowance (RDA) of vitamin B12 for adults is a mere 2.4 micrograms.
Macronutrients, on the other hand, are substances that your body requires in rather large quantities for proper health (i.e. carbohydrates, proteins, fats, water). For example, the RDA of fat for an adult consuming a 2000-calorie diet is about 60 grams, which is a whopping 25 million times the RDA of vitamin B12. This goes to show just how intricate and delicate your body’s physiology is.
A typical B vitamin "complex" supplement that you find over-the-counter will likely consist of:
- Vitamin B1 (Thiamine)
- Vitamin B3 (Niacin)
- Vitamin B5 (Pantothenic acid)
- Vitamin B6 (Pyridoxine)
- Vitamin B9 (Folic acid)
- Vitamin B12 (Cobalamin)
Nonetheless, there are other B vitamins that are vital for life, including vitamin B2 (riboflavin) as well as vitamin B7 (biotin); the former is particularly important for energy production while the latter is crucial for hair and skin health.
If you're curious why particular numbers are absent from the collection of B vitamins, such as vitamin B4 (choline), B8 (inositol), and B10 (para-aminobenzoic acid/PABA), it's because they're no longer technically vitamins, and are instead considered “pseudovitamins” or “vitamin-like” macronutrients.
How the Primary B Vitamins Work
B vitamins play many roles, such as controlling cholesterol levels, cellular respiration, neurotransmission, DNA repair, and creating blood cells. Due to their extreme complexity and unique actions, we will discuss each primary B vitamin separately in the following subsections.
Vitamin B1 (Thiamine)
Acting as a coenzyme, thiamine is mainly liable for converting glucose (sugar) and amino acids into functional energy, as well as growth of red blood cells. Despite deficiency of thiamine being particularly uncommon, consumers of alcohol tend to be at higher risk, especially if there is damage to the intestinal linings.
When thiamine deficiency is present, danger of type-2 diabetic issues increases rather dramatically from irregular blood sugar balance. In addition, thiamine is a vital micronutrient for manufacturing acetylcholine - an excitatory neurotransmitter that promotes focus, cognition, and motivation.
Vitamin B3 (Niacin)
Niacin plays is an integral part of oxidation-reduction reactions, which are the basis of cellular respiration - the process by which cells transform biochemical energy from nutrients into ATP (adenosine triphosphate). This vitamin is also mainly in charge of managing blood lipid levels by impeding the breakdown of fatty acids in the body; in turn, cholesterol synthesis decreases (particularly low-density lipoproteins, aka "bad" cholesterol).
Furthermore, niacin elevates the production of a peptide in humans called brain-derived neurotrophic factor (BDNF). This peptide acts on neurons throughout the brain to encourage development and replication, two key processes that reflect cognitive function.
Niacin deficiency, which typically only occurs in malnourished individuals, is known to create a disease called pellagra. This illness is related to significant mental disease such as dementia. Fortunately, moderate doses of niacin can potentially reverse the condition.
Vitamin B5 (Pantothenic acid)
Perhaps the most vital function of pantothenic acid in the human body is its action in forming coenzyme A, which later becomes acetyl-CoA – a molecule that is crucial for metabolism and energy production. Pantothenic acid must first be transformed to pantetheine (the active form of vitamin B5) by your body before it’s usable. At this time, there are no known conditions linked with pantothenic acid deficiency, however data does contend that supplementing with vitamin B5 could decrease LDL (i.e. " bad") cholesterol levels.
Vitamin B6 (Pyridoxine)
In similar fashion to thiamine, pyridoxine is necessary for metabolizing macronutrients, and is also utilized in production of red blood cells. Additionally, there are upwards of 160 known vital reactions in the body in which pyridoxal phosphate - the active form of vitamin B6 – is necessary for.
Moreover, pyridoxal phosphate is required for conversion of levodopa to dopamine, along with conversion of glutamate to GABA and proper metabolism of L-tryptophan (which is a precursor to serotonin). Therefore, numerous cognitive malfunctions can arise in individuals lacking vitamin B6.
Pyridoxine deficiency is most typical in chronic alcoholics and can cause depression, anemia, high blood pressure, sleeping disorders, neuropathy, as well as a variety of deleterious health conditions.
Naturally, it behooves you to limit alcohol consumption if you want to avoid any B vitamin-related deficiencies.
Vitamin B9 (Folic acid)
Folic acid is vital for nearly every physical reaction in the body that involves a one-carbon transfer, operating in combination with vitamin B12 to create and fix DNA, along with hemoglobin - a protein in red blood cells that delivers oxygen to tissues.
Being deficient in folic acid is rather uncommon as it is created by your intestinal bacteria; in extreme cases, malnourished people may become anemic due to lack of this vitamin. Moreover, too much folic acid in the body can hinder zinc absorption and cause convulsions, so superfluous intake of this vitamin is discouraged and unnecessary.
Vitamin B12 (Cobalamin)
Biochemically speaking, cobalamin is the most complex vitamin. Along with its complex nature, cobalamin plays crucial roles in the brain and central nervous system (which are fittingly the most complex parts of your body). Along with folic acid, cobalamin functions to produce DNA and is associated with metabolism of all the amino acids synthesized in your body.
Methylcobalamin is one of the most common forms of this vitamin present in your body as it's associated with methyl group-transfer reactions (which are rather numerous as part of your metabolism). Furthermore, metabolism of cobalamin is highly complex, making it one of the most common B vitamin deficiencies for human beings.
Cobalamin deficiency can result in serious, irreversible health defects, such as structural damage to the brain and nervous system, or even pernicious anemia (lack of red blood cell manufacturing). This is why doctors generally suggest cobalamin shots to patients who are severely lacking this vitamin.
Moreover, cobalamin is necessary for your body to convert homocysteine to methionine; methionine is an amino acid that the body uses for synthesizing S-adenosyl-methionine (SAMe), which then goes onto create various catecholamines and other important biomolecules. Hence, cobalamin is central to managing mood and cognition - by means of SAMe - as deficiency could lead to depression as well as high levels of anxiousness.
Advantages of Supplements with B Vitamins
Over-the-counter B vitamin supplements have been prominent for years. Research data so far pinpoints just how crucial these vitamins are for wellness as well as longevity, keeping in mind that shortages are correlated with greater risk of numerous health conditions.
In fact, a recent study goes so far as to suggest that specific B vitamins (B6 and B12) are efficacious for treating neurological conditions as well as other cognitive maladies. Vitamin B6 and vitamin B12 also appear to have strong implications in lowering stress/anxiousness as well as protecting neuronal integrity.
Moreover, vitamins B1, B3, B5, and B9 are important for DNA maintenance, energy production, cellular respiration, hormone regulation, blood lipid balance, and an array of other roles.
To summarize, the most relevant research-backed advantages of supplementing with the primary B vitamins includes:
- Natural stress- and anxiety-reducing properties
- Protect against excessive inflammation, cancer, and oxidative stress
- Promote feelings of calmness and relaxation
- Enhance the immune system and help ward off pathogens
- Manage cortisol/stress hormone manufacturing
Possible Side Effects from B Vitamin Supplementation
In general, quality B vitamin supplements are well-tolerated and practically risk-free when used in proper fashion. Frankly speaking, reaching a B vitamin toxicity is quite rare due to their water-soluble nature; excessive B vitamin buildup in your body means they can be rapidly excreted through urine to lower blood values accordingly.
That being said, be wary that vitamin B6 should not be used in amounts greater than 200 mg daily as high dosages of this vitamin can cause neurological complications. Likewise, vitamin B3 (when taken as nicotinic acid in high enough doses) will cause flushing of the face and skin, which is undesirable for many people. Inositol hexanicotinate typically circumvents this issue as it slowly releases niacin into your body.
Extremely high dosages of B vitamins could induce acute side results such as:
- Urinating frequently
Unless you’re ingesting upwards of 10 grams of B vitamins each day then you shouldn’t experience these side effects. If you begin to experience unwanted adverse effects after taking B vitamins, stop further usage immediately and they will likely go away. You may then try a lower dose later and assess your response.
B vitamins present perhaps the most traditional over-the-counter choice for total health and longevity support. One of the most worthwhile B vitamins for brain health and mental function is vitamin B12; however, research is ongoing to reveal the mechanisms behind B vitamins as cognitive enhancers.
Furthermore, B vitamins are arguably the most important group of vitamins for humans, making their usage tough to argue against (particularly if deficiencies are present). Thanks to their affordability and myriad health-promoting properties, B vitamin supplements (in the right forms) are a superb option for boosting cognition, managing mood, and just generally keeping you healthy.
Nevertheless, your best bet is to consume at least five servings of green vegetables per day (along with other vegetables and fruits) to meet your micronutrient/B vitamin demands. Supplements should never be the foundation of your B vitamin intake.