Vitamin B is not just one single vitamin; it is a family of vitamins, the functionality of each differing with effects ranging from fat burning to mood enhancement. Working with both the brain and the body, there are many benefits to having a sufficient supply of B Vitamins.

B Vitamins Explained

B vitamins work in conjunction with each other, but also have unique benefits on their own. 

Most of the B vitamins are recognised by their numbers: B1, B2, B3, B4, B5, B6, B7, B8, B9 and B12. They also have names that people may also recognise, namely: Thiamine, Riboflavin, Niacin, Choline, Pantothenic Acid, Pyridoxine, Biotin, Inositol, Folic Acid and Cobalamine.

The B vitamins are actually a group of eight water soluble vitamins, and 3 compounds that are associated wtih the B vitamin family (vitamin B4, vitamin B8 and PABA) that often coexist in the same foods.

Each B vitamin plays a distinct role in metabolism and energy production. When referring to all eight vitamins at once, it is known as the vitamin B complex.

Below we will explore each vitamin compound in more detail:

Thiamine (Vitamin B1)

Thiamine plays a vital role in metabolism, nerve function and the generation of energy from carbohydrates. It is involved in RNA and DNA production, and also plays an active roll in the Krebs cycle by converting carbohydrates to glucose. Thiamine can be used to treat anemia, paralysis, movement and memory disorders, energy loss and depression.

Thiamine can be found in cereal, meat, bread, rice, nuts, yeast and corn.

Riboflavin (Vitamin B2)

Riboflavin plays an important role in maintaining mucous membranes, nerve sheaths, eyes and skin. Riboflavin deficiency can lead to oral and skin problems as well as anemia. Riboflavin supplements can be used for preventing migraine headaches, cataracts of the eyes, and to treat blood disorders such as red blood cell aplasia and congenital methemoglobinemia.

Riboflavin can cause the urine to turn a yellow-orange color, though this is not dangerous, however large doses can cause diarrhea.

Riboflavin can be found in grains, meat, milk, peas, cheese and eggs.

Niacin (Vitamin B3)

Niacin, also known as vitamin B3, exists in two main forms: nicotinic acid and nicotinamide. Both forms play a crucial role in energy metabolism by serving as precursors for coenzymes like NAD and NADP. Nicotinic acid has lipid-modifying effects, influencing cholesterol levels, while nicotinamide is known for its benefits to skin health and is commonly used in skincare products.

Niacin plays a vital role in metabolism and helps to maintain the gastrointestinal tract, the skin, and nerves. Niacin insufficiency can lead to a disease called pellagra which is defined as a set of symptoms that includes dementia, dermatitis and diarrhea.

Niacin is generally used for reducing high cholesterol and treating pellagra. However, cramps, nausea, itching, flushing and skin breakouts can occur if too much niacin is taken.

For a healthy, balanced diet it’s important to obtain niacin from dietary sources. Niacin can be found in meat, potatoes, legumes, milk, eggs and fish.

Choline (Vitamin B4)

Choline is an essential nutrient that plays several important roles in the body. It is often grouped with the B vitamins due to its similar functions and is sometimes referred to as vitamin B4, although it is not officially classified as a vitamin. Choline is crucial for various physiological processes, including; Cell Membrane Structure, Neurotransmitter Synthesis, Liver Health, Brain Development, Methylation Reactions, Muscle Function .

Although the body can synthesize some choline on its own, dietary sources are important for meeting daily needs, especially during periods of increased demand such as pregnancy and lactation. Pregnant and breastfeeding women, in particular, may need higher intakes of choline to support the developing fetus and infant.

Choline is found in various foods, including eggs, meat, fish, dairy products, nuts and soybeans.

Pantothenic acid (Vitamin B5)

Pantothenic acid helps with the breakdown of carbohydrates, amino acids and lipids. There is very little scientific evidence to support the use of vitamin B5 as a supplement. Pantothenic acid can be found in legumes, meats and whole grain cereals.

Pyridoxine (Vitamin B6)

Pyridoxine plays an important role in metabolism and the production of amino acids. Low pyridoxine levels can lead to mouth irritation, skin and nerve damage and confusion. Pyridoxine can be used to treat sideroblastic anemia and reduce high levels of homocysteine which is a substance thought to play a role in heart disease. An IV injection of pyridoxine can also treat some types of infant seizures. However, an overdoses of pyridoxine can cause nerve damage.

Pyridoxine can be found in organ meats, fish, soybeans, butter and brown rice.

Biotin (Vitamin B7)

Biotin is a critical coenzyme in the caroboxylation reactions of the Krebs cycle. It plays a vital role in the conversion of carbohydrates to glucose. Biotin is used to treat scaly dermatitis which is a skin disorder affecting mainly the scalp, face and torso. It is also used to treat hair loss, depression and exhaustion.

Biotin can be found in egg yolks, mushrooms, brewer’s yeast and beef liver.

Inositol (Vitamin B8)

Inositol is a naturally occurring compound that belongs to the vitamin B family, although it is not officially classified as a vitamin. It is often referred to as vitamin B8, but because it can be synthesized by the body, it is not considered an essential nutrient.

Inositol is found in many foods, particularly fruits, beans, grains and nuts. It is also produced by the body from glucose and is present in all human tissues, particularly in the brain and central nervous system.

Inositol is available as a dietary supplement in various forms, including myo-inositol and D-chiro-inositol. It is often used for its potential therapeutic effects in conditions such as PCOS, mood disorders and metabolic syndrome.

Folic Acid (Vitamin B9)

Folic acid is famous for preventing birth defects in pregnant women. It is a very important vitamin because it plays a vital role in fetal brain and nerve development. Low folic acid levels can lead to birth defects and poor growth.

Less well known is the fact that folic acid is also useful for; preventing cancer, lowering the risk of heart disease, protein metabolism, reducing mouth irritation, DNA and hemoglobin synthesis, red blood cell formation and helping to prevent anemia. Folic acid can also be used for reducing homocysteine levels in people with renal disease and to reduce the harmful effects of methotrexate.

However, large amounts of folic acid can result in poor zinc absorption and convulsions.

Folic acid can be found in liver, green vegetables, yeast and whole grain cereal.

Cobalamin (Vitamin B12)

Cobalamin is the only B vitamin that does not exist in plants, which can be a major concern for vegans. Cobalamin can be found in meat, liver, eggs, milk and poultry.

Like other B vitamins, Cobalamin plays a critical role in blood cell formation, the metabolism of food and DNA synthesis. Pernicious anemia, mouth irritation and brain damage are all major side effects of a Cobalamin deficiency.

Most vitamin B12 deficiencies are due to the stomach’s inability to produce intrinsic factor, which is an enzyme that helps the intestines absorb vitamin B12. Therefore, if vitamin B12 is administered it must be accompanied with intrinsic factor.

Para-aminobenzoic Acid (PABA)

Para-aminobenzoic acid (PABA) is a compound that is structurally similar to the B vitamins and was once thought to be a member of the vitamin B complex. However, it is now classified as a non-essential nutrient, meaning that the body can synthesize it on its own, and it is not considered a vitamin.

Health Benefits of B Vitamins

Vitamin B in its various forms has many health benefits, which we will explore below:

Vitamin B for Energy

Vitamin B, particularly certain forms such as B6 and B12, play essential roles in energy metabolism and overall cellular function. However, taking vitamin B supplements is unlikely to provide an immediate “buzz” of energy in the same way that caffeine or other stimulants might.

Here’s how vitamin B contributes to energy levels:

Energy Metabolism: B vitamins are involved in converting carbohydrates, fats, and proteins from the foods we eat into energy that our cells can use. They help facilitate various biochemical reactions in the body, including those within the mitochondria, the cellular powerhouses responsible for producing ATP (adenosine triphosphate), the primary energy currency of the cell.

Red Blood Cell Production: Vitamin B12 and folate (another B vitamin) are necessary for the production of red blood cells, which transport oxygen throughout the body. Adequate oxygen delivery is crucial for maintaining energy levels and supporting overall cellular function.

Nervous System Function: B vitamins are essential for maintaining the health and function of the nervous system. They help produce neurotransmitters, which are chemical messengers that transmit signals between nerve cells. A well-functioning nervous system is important for regulating energy levels, mood, and cognitive function.

While vitamin B deficiencies can lead to symptoms such as fatigue, weakness, and lethargy, taking B vitamin supplements is generally only beneficial for individuals with diagnosed deficiencies or certain medical conditions that affect absorption or metabolism of these vitamins.

If you’re feeling consistently fatigued or low on energy, it’s essential to address the underlying causes, which may include inadequate sleep, poor nutrition, stress, or underlying health conditions.

B Vitamins Enhance Brain Power

B vitamins enable your brain to function better. B vitamins play crucial roles in supporting brain power by contributing to energy metabolism, neurotransmitter synthesis, DNA repair, and the maintenance of nerve function. Adequate intake of these nutrients is crucial for maintaining optimal brain power.

A balanced diet rich in B vitamin-containing foods, such as whole grains, lean meats, fish, dairy products, fruits and vegetables, can help support optimal brain health and cognitive function. Additionally, supplementation with B vitamins may be beneficial for individuals with deficiencies or specific cognitive concerns.

Here’s how some B vitamins contribute to brain health:

Thiamine (Vitamin B1): Thiamine is involved in energy metabolism and is essential for the production of ATP, the primary energy source for cells, including brain cells. Adequate thiamine levels support proper brain function and help maintain focus and alertness.

Riboflavin (Vitamin B2): Riboflavin is involved in energy production and helps support healthy brain function. It acts as a cofactor for enzymes involved in the metabolism of carbohydrates, fats, and proteins, providing the brain with the energy it needs to function optimally, and can help migraine sufferers by supporting energy metabolism, acting as an antioxidant, aiding in neurotransmitter synthesis, and improving mitochondrial function.

Supplementation with high doses of riboflavin has been shown to reduce the frequency and severity of migraine attacks in some individuals.

Niacin (Vitamin B3): Niacin is important for DNA repair and the production of neurotransmitters, including serotonin, dopamine, and norepinephrine, which are involved in mood regulation, concentration, and cognitive function. Adequate niacin levels support overall brain health and cognitive performance.

Vitamin B4 (Choline): While not officially classified as a B vitamin, choline is often grouped with B vitamins due to its similar functions. Adequate choline intake supports cognitive function and brain health, and may help reduce brain fogginess and improve memory. It is a precursor to acetylcholine, a neurotransmitter that plays a crucial role in memory, learning and muscle control.

Pyridoxine (Vitamin B6): Pyridoxine plays a crucial role in neurotransmitter synthesis, including serotonin and dopamine, which are important for mood regulation and cognitive function. It works with the brain’s neurotransmitters, particularly those that release serotonin. This can enhance your mood and relieve symptoms of premenstrual syndrome.

Vitamin B6 also supports the production of hemoglobin, which transports oxygen to the brain, and helps regulate homocysteine levels, which can affect cognitive function.

Inositol (vitamin B8): Inositol has mood-altering capabilities said to reduce depression and anxiety. It is abundant in the brain and is thought to play a role in maintaining overall brain health and function. It has been studied for its potential therapeutic effects in various neurological and psychiatric conditions, including depression, anxiety, and bipolar disorder.

Folate (Vitamin B9): Folate is involved in DNA synthesis and methylation processes in the brain. It plays a crucial role in neurotransmitter synthesis and helps regulate homocysteine levels, which are associated with cognitive decline and neurodegenerative diseases.

Cobalamin (Vitamin B12): Vitamin B12 is essential for the maintenance of myelin, a fatty substance that insulates nerve fibers and facilitates efficient nerve signaling. It also plays a role in DNA synthesis and neurotransmitter metabolism, supporting overall brain health and cognitive function. Similar to vitamin B4, B12 may also help you reduce brain fogginess and improve memory.

B Vitamins for Cellular Signalling

B vitamins play crucial roles in cellular signaling pathways, which involves the transmission of signals within and between cells to regulate various physiological processes. Cellular signalling regulates various physiological processes, including energy metabolism, neurotransmitter synthesis, DNA repair and gene expression.

Adequate intake of B vitamins through diet or supplementation is essential for maintaining optimal cellular function and overall health.

Here’s how B vitamins contribute to cellular signaling:

Thiamine (Vitamin B1): Thiamine is involved in cellular signaling pathways related to energy metabolism. It serves as a cofactor for enzymes involved in the conversion of carbohydrates into energy, helping to regulate glucose metabolism and maintain cellular energy levels.

Riboflavin (Vitamin B2): Riboflavin is a component of flavin adenine dinucleotide (FAD) and flavin mononucleotide (FMN), coenzymes that play crucial roles in cellular signaling pathways. FAD and FMN participate in oxidation-reduction reactions that are necessary for various metabolic processes, including energy production and the synthesis of molecules such as ATP.

Niacin (Vitamin B3): Niacin is involved in cellular signaling pathways related to DNA repair, gene expression, and metabolism. It serves as a precursor for the synthesis of nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phosphate (NADP), which are coenzymes involved in redox reactions and other cellular processes.

Pyridoxine (Vitamin B6): Pyridoxine is involved in cellular signaling pathways related to neurotransmitter synthesis, amino acid metabolism, and gene expression. It serves as a cofactor for enzymes involved in the synthesis of neurotransmitters such as serotonin, dopamine, and gamma-aminobutyric acid (GABA), which play crucial roles in neuronal signaling and brain function.

Biotin (Vitamin B7): Biotin is involved in cellular signaling pathways related to gene expression, cell proliferation, and metabolism. It serves as a cofactor for carboxylase enzymes involved in the synthesis of fatty acids, amino acids, and glucose, which are essential for cellular growth and function.

Inositol (vitamin B8): Inositol is important for neurotransmitter function. It plays a crucial role in cellular signaling pathways, acting as a second messenger in response to various hormones and neurotransmitters. It is involved in regulating important cellular processes such as cell growth, differentiation, and apoptosis (programmed cell death). It is a precursor to various neurotransmitters, including serotonin, dopamine and norepinephrine, which play key roles in mood regulation, cognition and emotional well-being.

Folate (Vitamin B9): Folate is involved in cellular signaling pathways related to DNA synthesis, methylation, and repair. It serves as a cofactor for enzymes involved in the transfer of one-carbon units, which are essential for the synthesis of nucleotides and the methylation of DNA and proteins.

Cobalamin (Vitamin B12): Vitamin B12 is involved in cellular signaling pathways related to DNA synthesis, methylation, and nerve function. It serves as a cofactor for enzymes involved in the conversion of homocysteine to methionine, which is important for DNA synthesis and methylation reactions.

B Vitamins for Body Healing

B vitamins play vital roles in speeding up the body’s healing processes by supporting various physiological functions involved in tissue repair and regeneration.

Here’s how B vitamins contribute to body healing:

Energy Production: B vitamins are essential for converting carbohydrates, fats, and proteins into energy that the body can use for cellular processes, including tissue repair. Adequate energy production is crucial for providing the energy needed to fuel healing processes.

Cellular Growth and Division: B vitamins are involved in DNA synthesis and cell division, which are essential for the growth and regeneration of tissues. Folate (B9) and cobalamin (B12) are particularly important for DNA synthesis and cell proliferation. Niacin, (vitamin B3), can increase a person’s energy to help with DNA repair and bodily healing. Pantothenic Acid, (vitamin B5), works similarly to B3, but is more involved with actual wound healing.

Collagen Synthesis: Vitamin C works closely with several B vitamins, particularly riboflavin (B2), niacin (B3), and pyridoxine (B6), to support the synthesis of collagen, a protein that provides structure and strength to tissues. Collagen is essential for wound healing and tissue repair.

Immune Function: B vitamins support immune function by promoting the production and activity of immune cells involved in the inflammatory response and tissue repair. Adequate intake of B vitamins helps maintain a robust immune system, which is essential for combating infections and supporting healing processes.

Antioxidant Defense: Some B vitamins, such as riboflavin (B2) and niacin (B3), have antioxidant properties that help neutralize harmful free radicals generated during the healing process. By reducing oxidative stress and inflammation, B vitamins support tissue repair and prevent further damage to tissues.

Nerve Function: Vitamin B12 is essential for nerve health and function. It plays a crucial role in the maintenance of myelin, a fatty substance that insulates nerve fibers and facilitates efficient nerve signaling. Adequate vitamin B12 levels are essential for proper nerve function and tissue repair.

Blood Cell Formation: Vitamin B6 is involved in the synthesis of hemoglobin, the protein in red blood cells that carries oxygen to tissues. Adequate intake of vitamin B6 supports the production of healthy red blood cells, which are essential for delivering oxygen and nutrients to healing tissues.

Overall, B vitamins are essential for supporting the body’s healing processes by promoting energy production, cellular growth and division, collagen synthesis, immune function, antioxidant defense, nerve function and blood cell formation.

A balanced diet rich in B vitamin-containing foods, such as whole grains, lean meats, fish, dairy products, fruits, and vegetables, can help support optimal healing and recovery. Additionally, supplementation with B vitamins may be beneficial for individuals with deficiencies or specific healing needs.

B Vitamins for Lipid Metabolism

B vitamins play important roles in lipid metabolism, the process by which the body breaks down and utilizes fats for energy, storage, and other physiological functions.

Several B vitamins are directly involved in various aspects of lipid metabolism:

Riboflavin (Vitamin B2): Riboflavin is a component of flavin adenine dinucleotide (FAD) and flavin mononucleotide (FMN), coenzymes that are involved in various metabolic pathways, including lipid metabolism. FAD and FMN participate in oxidation-reduction reactions that are necessary for the breakdown and utilization of fats for energy.

Niacin (Vitamin B3): Niacin is essential for the synthesis of nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phosphate (NADP), coenzymes that play key roles in cellular energy production and lipid metabolism. Niacin also helps regulate lipolysis, the breakdown of fats stored in adipose tissue.

Pantothenic Acid (Vitamin B5): Pantothenic acid is a component of coenzyme A (CoA), which is required for the synthesis and breakdown of fatty acids. CoA is necessary for the activation of fatty acids before they can be metabolized in the mitochondria.

Pyridoxine (Vitamin B6): Pyridoxine is involved in fatty acid metabolism through its role in amino acid metabolism. It is a cofactor for enzymes involved in the synthesis of non-essential amino acids, some of which are precursors to fatty acid synthesis.

Biotin (Vitamin B7): Biotin is involved in fatty acid synthesis, a process in which fatty acids are produced from acetyl-CoA. Biotin serves as a cofactor for carboxylase enzymes, which are necessary for the synthesis of fatty acids from precursor molecules.

Inositol (vitamin B8): Inositol is involved in lipid metabolism, including the synthesis and breakdown of fats. It plays a role in regulating cholesterol levels and triglyceride levels in the blood.

Folate (Vitamin B9): Folate is involved in one-carbon metabolism, which is important for the synthesis of nucleic acids and the metabolism of amino acids. Folate deficiency can lead to elevated levels of homocysteine, which has been associated with impaired lipid metabolism and increased risk of cardiovascular disease.

Cobalamin (Vitamin B12): Vitamin B12 is involved in the metabolism of fatty acids and amino acids. It acts as a cofactor for methionine synthase, an enzyme involved in the conversion of homocysteine to methionine. Methionine is essential for the synthesis of S-adenosylmethionine (SAMe), a methyl donor involved in various metabolic pathways, including lipid metabolism.

Overall, B vitamins are essential for lipid metabolism and overall energy metabolism in the body. Adequate intake of B vitamins through diet or supplementation is important for maintaining optimal lipid levels and supporting overall health. However, it’s essential to obtain these nutrients through a balanced diet rather than relying solely on supplements.

B Vitamins for Insulin Sensitivity

Several B vitamins play important roles in supporting insulin sensitivity, which is crucial for maintaining normal blood sugar levels and preventing insulin resistance.

Here’s how some B vitamins are involved in insulin resistance:

Thiamine (Vitamin B1): Thiamine is involved in glucose metabolism and energy production. It plays a role in the conversion of carbohydrates into energy and helps regulate glucose levels in the blood. Thiamine deficiency has been associated with impaired glucose tolerance and insulin resistance.

Riboflavin (Vitamin B2): Riboflavin is involved in energy metabolism and may play a role in insulin sensitivity. It is a component of flavin adenine dinucleotide (FAD), a coenzyme involved in various metabolic pathways, including those related to glucose metabolism.

Niacin (Vitamin B3): Niacin is important for the metabolism of carbohydrates, fats, and proteins. It helps regulate blood sugar levels and may improve insulin sensitivity. Niacin supplementation has been shown to reduce insulin resistance in some studies.

Pyridoxine (Vitamin B6): Pyridoxine is involved in glucose metabolism and insulin action. It plays a role in glycogenolysis (the breakdown of glycogen into glucose), gluconeogenesis (the synthesis of glucose from non-carbohydrate sources), and insulin signaling pathways. Vitamin B6 deficiency has been associated with impaired glucose tolerance and insulin resistance.

Biotin (Vitamin B7): Biotin is involved in carbohydrate metabolism and may help improve insulin sensitivity. Biotin, (vitamin B7), when used in combination with chromium, shows promise to help blood-sugar control. It acts as a cofactor for enzymes involved in the breakdown of glucose and fatty acids for energy.

Inositol (vitamin B8): Inositol has been studied for its potential role in improving insulin sensitivity and glycemic control, particularly in individuals with insulin resistance and conditions such as polycystic ovary syndrome (PCOS).

Folate (Vitamin B9): Folate is involved in one-carbon metabolism, which is important for DNA synthesis and repair, as well as the metabolism of amino acids and neurotransmitters. Folate deficiency has been associated with insulin resistance and an increased risk of type 2 diabetes.

Cobalamin (Vitamin B12): Vitamin B12 is involved in energy metabolism and may play a role in insulin sensitivity. It acts as a cofactor for methionine synthase, an enzyme involved in the metabolism of homocysteine, a compound that has been linked to insulin resistance and type 2 diabetes.

Overall, B vitamins play important roles in supporting insulin sensitivity and glucose metabolism. A balanced diet that includes a variety of foods rich in B vitamins, such as whole grains, lean meats, fish, dairy products, fruits, and vegetables, can help support overall health and may help improve insulin sensitivity.

However, it’s important to note that while B vitamins can support overall health, they are not a cure for insulin resistance or type 2 diabetes, and treatment should be individualized under the guidance of a healthcare professional.

Vitamin B Deficiency

Vitamin B is available in dark green vegetables, grains, and meat, but the problem is getting enough in your regular diet. Deficiencies of vitamin B6 and B12 are very common in the general population. In addition, as one ages the ability to absorb vitamin B can become compromised, such as by stomach disorders or other prescribed medications. Pregnancy also draws heavily on your bodies vitamin stores. This is where supplementation is often considered.

How to Consume Vitamin B

Eating a well balanced diet containing whole grain foods, meat, dairy and vegetables is the best way to achieve a healthy balance of B vitamins.

Vitamin B Supplements

Oral Supplements are only partially absorbed by the body, but are sometimes medically necessary when absorption problems or malnutrition occur. Supplementation with B vitamins is usually done via a complex formula that has all 11 B vitamin forms in it; however, you can get just a single B vitamin form if you prefer.

Most people only need supplementation with capsules, tablets or liquids. For extreme deficiencies, shots of B12 may be recommended by a physician who wants to bypass the absorption mechanism altogether.

Vitamin B12 Injections

Injectable vitamin B12 is often prescribed for individuals who have difficulty absorbing vitamin B12 from food or oral supplements, such as those with pernicious anemia, gastrointestinal disorders, or those who have undergone certain types of surgeries that affect nutrient absorption.

The injection form of vitamin B12 allows for direct absorption into the bloodstream, bypassing the gastrointestinal tract, which may be compromised in individuals with absorption issues. This method ensures efficient delivery of vitamin B12 to the body, particularly for those with severe deficiencies or conditions that impair absorption.

While other B vitamins can also be administered via injection in certain medical contexts, vitamin B12 is the most commonly used form for injections due to its role in various physiological processes and its relevance in the treatment of specific conditions such as anemia and neuropathy.

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Vitamin B Notes / Side Effects

B vitamins shouldn’t be ingested on an empty stomach. They can make you nauseous if they are not taken with food. Ideally, the tablet should be taken after a meal and earlier in the day, not later. Since B vitamins boost energy levels, they can act as a stimulant and also cause a restless sleep. Look for supplements that have the recommended daily value and do not try to overload your system unless under a doctor’s orders to increase the levels substantially.

B vitamins tend to be very safe at recommended levels. They do turn the urine a strong yellow color, but this is not harmful. However, if you take too much Niacin (B3), then you could cause some flushing and liver damage. You won’t be overloading your system with a regular multivitamin supplement, but sometimes doctor’s prescribed much higher doses of Niacin when they are trying to help patient’s control their cholesterol levels.

One other vitamin with a serious side effect when taken in large doses is vitamin B6. It will cause nerve damage if taken in excessive dosages. Taking 200mg or more a day of vitamin B6 [LK2] can lead to a loss of feeling in the arms and legs known as peripheral neuropathy. To remain safe make sure that your vitamin B6 is only 200 mg or less each day.