The Function, Source, & Power of B-Vitamins Unlocked

A substance required by the body to function, but not made by the body, is by definition a vitamin.

B-vitamins are a very important group of substances that needed for various functions, including:

• Making DNA and proteins
• Detoxifying
• Breaking down amino acids
• Converting one molecule to another
• And making energy

They do this by providing an essential ingredient in the function of enzymes. Enzymes change molecules, but they often need something to make that change. The B-vitamins are an unrelated group of eight water-soluble vitamins that each provide a different essential ingredient for enzymes to function.[1] They are lumped together for several reasons:

1. Water Solubility: All B-vitamins are water-soluble.
2. Coenzyme Function: B-vitamins serve cofactors, which means they are essential for the proper functioning of enzymes.
3. Interconnected Functions: B-vitamins often work in concert with each other in metabolic pathways. For example, vitamin B6 is essential for the conversion of tryptophan (an amino acid) to niacin (vitamin B3). Similarly, DNA synthesis and red blood cell formation involve folate (vitamin B9) and vitamin B12; and they complement each other’s functions.
4. Deficiency Symptoms: Deficiency in any of the B-vitamins can lead to a range of similar symptoms, including fatigue, weakness, anemia, skin problems, and neurological issues. Since vitamins were discovered before it was known how they functioned, it made sense to put them together based on symptoms of deficiency.

While they are grouped together for convenience, each B-vitamin is unique and serves essential functions in the body. There are eight B-vitamins:

• Vitamin B1 (Thiamine)
• Vitamin B2 (Riboflavin)
• Vitamin B3 (Niacin)
• Vitamin B5 (Pantothenic Acid)
• Vitamin B6 (Pyridoxine)
• Vitamin B7 (Biotin)
• Vitamin B9 (Folic Acid)
• Vitamin B12 (Cobalamin)

Your next question is, “What happened to vitamin B4, B8, B10, and B11?”[2] These were once thought to be vitamins, but because the body makes these, or they aren’t essential in the diet, they are not true vitamins.

• Vitamin B4 — adenine, which is one of the four building blocks of DNA and RNA.
• Vitamin B8 — inositol, a vital component of cell membranes, and other functions.
• Vitamin B10 — para-aminobenzoic acid (PABA).
• Vitamin B11 — pteryl-hepta-glutamic acid, or salicylic acid.

B-vitamins mostly do not become toxic, even in high doses, because they are water soluble, and the kidney will excrete what is not used. However, the liver can store them for later use so it’s hard to get deficiency. More on this when we discuss dosing. They come from different sources in the diet. For example, Vitamin B9 (Folic acid) comes from green vegetables, while vitamin B12 is only made by bacteria in the bowels. There are no plant sources of vitamin B12.

Each of these vitamins affects your life in different ways.

Vitamin B1

Thiamine is essential for converting carbohydrates into energy and maintaining proper nerve function by aiding in the synthesis of neurotransmitters, especially acetylcholine, which is necessary for memory. It also plays a role in muscle contraction, amino acids, and energy metabolism, and contributes to the formation of nucleic acids, which are the building blocks of DNA.

Since it is essential for energy production in the heart, people who take medications such as furosemide (Lasix) lose thiamine in the urine leading to worsening heart failure. Alcohol can also inhibit the absorption of thiamine, leading to neuropathy associated with alcohol abuse.

You may need more vitamin B1 if you have:

• Diabetes
• Congestive heart failure
• Alzheimer’s disease
• Parkinson’s disease
• Huntington’s disease
• Cataracts

Thiamine is typically found in a variety of foods, including whole grains, legumes, nuts, pork, and vegetables. The normal amount consumed in food is about 2mg per day. Those who have deficiencies with neuropathy, such as diabetics may use 200mg to 400mg per day.

A synthetic form of thiamine, benfotiamine, is fat soluble so its absorption is better. It is also able to cross the blood-brain barrier, and therefore may be a better choice for neuropathy. It is dosed between 150 and 300mg per day.

Vitamin B2

Energy production, the breakdown of fats and toxins (drugs), and the maintenance of healthy skin and eyes involves riboflavin. Riboflavin is also important for the conversion of tryptophan to niacin (vitamin B3).

Energy Metabolism

Riboflavin is a crucial component of two coenzymes, flavin mononucleotide (FMN) and flavin dinucleotide (FAD) which convert carbohydrates, fats, and proteins from the food we eat into adenosine triphosphate (ATP), the body’s primary energy source.

Antioxidant Defense

Vitamin B2 plays a role in the body’s antioxidant defense system. FMN and FAD help regenerate the antioxidant glutathione, which protects cells from oxidative stress and damage caused by free radicals.

Eye Health

Riboflavin contributes to the health of the eyes. It is involved in the conversion of vitamin B6 (pyridoxine) into its active form, P5P, which is necessary for the synthesis of a pigment called rhodopsin in the retina. Rhodopsin is essential for vision, especially in low-light conditions.

Low-level riboflavin deficiency is relatively rare since it is found in many foods, including dairy products, meats, eggs, and green leafy vegetables. However, deficiencies can occur in individuals with limited dietary variety or certain medical conditions. Vitamin B2 is destroyed by light.

You may need vitamin B2 if you have:

• Migraine headaches
• Fatigue
• Dry, cracked lips
• Cataracts
• Poor night vision
• Hypertension
• High Homocysteine
• Abnormal MTHFR (folate)

Vitamin B3

Vitamin B3 comes in various forms, including niacin (nicotinic acid), niacinamide, (nicotinamide), and nicotinamide riboside. It is necessary for energy production, cell signaling, and DNA repair. It is also an anti-oxidant and regulates cholesterol levels. Because it affects such basic aspects of life, a deficiency can be devastating.

Niacin, or nicotinic acid, causes flushing in high doses. Niacinamide is also known as nicotinamide does not cause flushing even at very high doses.

The usual amount of vitamin B3 in the diet includes the amino acid tryptophan. Tryptophan is made into niacinamide, as well as serotonin, and melatonin. Thus, a deficiency of niacin may decrease the production of serotonin. It’s easy to see that this vitamin can affect every tissue in the body.

Niacin deficiency can lead to a condition called pellagra, which is characterized by symptoms such as dermatitis (skin inflammation), diarrhea, dementia, and, in severe cases, death.

Most healthy people get between 10mg and 20mg of niacin in their diet. Niacin and derivatives are found in meats, especially poultry and fish, as well dairy products, nuts, seeds, and grains.

You may need vitamin B3 if you have:

• Nervous system issues
• Digestive disorders
• Thickened, pigmented skin
• Fatigue, lack of energy

A supplemental dose of niacin may be around 500mg per day as niacinamide.

Vitamin B5

Every living creature contains pantothenic acid. It is not just important for humans, but for all life. It is necessary for the synthesis of fatty acids, cholesterol, and neurotransmitters. It also plays a role in the metabolism of carbohydrates, proteins, and fats into energy to run your body. It is also needed to make the hemoglobin that fills your red blood cells to carry oxygen to your cells. Vitamin B5 is important for detoxifying harmful substances in the liver through conjugation. It is also required to produce acetylcholine, a neurotransmitter involved in memory and muscle contractions.

Pantothenic acid deficiency is rare because it is widely available in a variety of foods, including meat, dairy products, eggs, whole grains, legumes, and nuts. The usual intake for most people is between 5mg and 10mg per day.

You may need extra vitamin B5 if you have:

• Fatigue
• Irritability
• Numbness or tingling in the hands and feet
• Gastrointestinal distress
• Premature gray hair
• Vascular disease
• Acne

A supplemental dose of pantothenic acid is around 250 to 500mg per day.

Vitamin B6

Pyridoxine is involved in over 100 enzyme reactions in the body, including the conversion of one amino acid into another, the synthesis of non-essential amino acids, and the breakdown of excess amino acids, and the synthesis of neurotransmitters including serotonin, dopamine, norepinephrine, and gamma-aminobutyric acid (GABA). B6 is also necessary to produce hemoglobin, the protein in red blood cells responsible for carrying oxygen throughout the body.

Immune Function

Vitamin B6 is involved in the production and activation of immune cells, particularly lymphocytes and T-cells, which play a crucial role in the body’s defense against infections.

Metabolism of Fats and Carbohydrates

B6 is needed for the metabolism of carbohydrates and fats, helping to convert these macronutrients into ATP for energy.

Hormone Regulation

Pyridoxine plays a role in hormone regulation, particularly in the synthesis and metabolism of steroid hormones like estrogen and testosterone.

Collagen

Vitamin B6 contributes to healthy skin and connective tissue by playing a role in the synthesis of collagen, a structural protein that gives strength to your bones, skin, tendons, and ligaments.

Homocysteine

B6 helps prevent the buildup of homocysteine, which, when elevated, is an increased risk of cardiovascular disease. A higher vitamin B6 intake is associated with one third lower risk of cardiovascular disease.[3]

A deficiency in vitamin B6 is relatively rare. The need is generally about 2mg per day. But if there is any stress, kidney problems, autoimmune diseases, increased alcohol intake, or taking certain medications, such as isoniazid, cyclosporine, valproic acid, phenytoin, carbamazepine, primidone, hydralazine, or birth control pills, the need could easily double.

You might need vitamin B6 if you have:

• Fatigue
• Depression
• Confusion
• Frequent infections
• Cardiovascular disease
• Morning sickness
• Low protein
• Connective tissue disorders
• Anemia
• High homocysteine
• Or if you are taking any of the medications listed above.

Overdose

Vitamin B6 is one of the few B-vitamins that can become toxic. People who take too much (over 500mg per day for months) can get neuropathy and hormone imbalances. The mistake people make is that since deficiency could cause the same symptoms, they may take more, and get worse. The symptoms go away when the vitamin is stopped.

Vitamin B6 is found in a variety of foods, including poultry, fish, meat, whole grains, nuts, seeds, beans, and bananas. Most people can obtain sufficient B6 from a well-balanced diet. However, certain groups, such as pregnant women and individuals with certain medical conditions, especially on medications, may require additional B6 intake.

Oral contraceptive use

Women taking oral contraceptives may need extra vitamin B6, as it is essential for hormone balance. The dose is about 100mg per day.

The usual dose of a supplement is around 50mg daily. Because of genetic enzyme abnormalities, some will need a special, or active form called pyridoxal-5-phosphate, or P5P.

Vitamin B7

Biotin is often referred to as the “beauty vitamin” because of its potential benefits for healthy hair, skin, and nails. But it is important in a lot of other reactions as well.

Metabolism of amino acids.

Skin, hair, and nails are made of a protein called collagen. Biotin is essential for the proper production of collagen.

Healthy Skin

Biotin also promotes cell growth and repair. It is often used in skincare products to help alleviate conditions like acne and dry skin. However, the topical application does not replace internal deficiency.

Healthy Hair

Biotin is sometimes recommended for individuals looking to promote hair growth and maintain healthy hair. While biotin deficiency can lead to hair loss, excessive biotin does not cause more hair growth. Enough is just enough. More is not better.

Strong Nails

Biotin promotes keratin production, which is the protein that makes up the hair and nails. A lack of biotin forms weak nails.

Metabolism of Carbohydrates

Biotin may help regulate blood sugar levels, making it potentially beneficial for individuals with diabetes or prediabetes.

Metabolism of Fats

Biotin is a cofactor for enzymes involved in the metabolism of fats, to convert it into ATP, the energy currency of the cell.

Fetal Development

Because it is so important in the production of proteins, biotin is crucial for normal fetal development, including the formation of the baby’s organs and limbs. Pregnant women require higher biotin intake to support these processes.

Healthy Nervous System

Biotin is involved in maintaining a healthy nervous system. It plays a role in nerve signaling and neurotransmitter function.

Biotin deficiency is relatively rare and typically occurs in individuals with certain medical conditions or those who consume excessive amounts of raw egg whites, as they contain a protein called avidin that can bind to biotin and reduce its absorption. Ironically, egg yolks are a good source of biotin – just cook the whites to denature the avidin. It seems the ideal way to eat an egg is with the white cooked and the yolk raw.

You may need more biotin if you have:

• Hair loss, or thin hair
• Skin rashes
• Dry skin
• Weak nails
• Fatigue
• Neurological issues

Biotin is naturally found in various foods, including egg yolks, liver, nuts, seeds, and many vegetables. The daily amount needed is less than 1,000 micrograms (1mg) and most supplements are about 5mg.

Vitamin B9

Vitamin B-9 is otherwise known as folic acid, folate, methylfolate, folinic acid, or 5- The body cannot use folic acid, even though it comes from plants. It must be converted to the active form, MTHF, by an enzyme known as MTHFR (5,10-methylenetetrahydrofolate reductase). Without this enzyme, you can take all the folic acid you want, but it won’t work. This is why it is good to know if you have a genetic variation in the MTHFR gene. Those who do can supplement their diet with MTHF and have a normal function of vitamin B9. This nutrient is essential for many functions in the body:

DNA synthesis and Repair

Folate is critical for the synthesis and repair of DNA, the genetic material in our cells. It plays a fundamental role in cell division and growth. Adequate folate levels are particularly crucial during periods of rapid cell division, such as pregnancy and childhood. The chemotherapy drug, methotrexate, blocks folate so the cancer cells stop dividing, so the antidote to poisoning by methotrexate is MTHF.

Red Blood Cell Formation

Folate is necessary to produce red blood cells, which transport oxygen throughout the body. A deficiency in folate can lead to a type of anemia called megaloblastic anemia, characterized by enlarged and underdeveloped red blood cells.[4]

Prevention of Neural Tube Defects

Folate is essential during early pregnancy to prevent neural tube defects in the developing fetus. Lack of folate slows the development of the brain and spinal cord because DNA requires folate for cell division. During this phase of development as the neural tube is being made into a spinal cord, the cells are dividing so rapidly, they need much more folic acid to make the necessary amount of DNA. A pregnant woman needs two to ten times the amount of folic acid as a woman who is not pregnant, so it is helpful to use a supplement during these times.[5]

Amino Acid Metabolism

The metabolism of certain amino acids, including homocysteine, involves folate. Methylfolate is needed to convert homocysteine to methionine.[6] If there isn’t enough MTHF, homocysteine builds up, leading to heart disease.

Methylation Reactions

Folate is a cofactor in various methylation reactions in the body. Methylation is a crucial biochemical process that regulates gene expression (turning genes on or off), detoxifies harmful substances, and helps repair DNA.

Immune Function

Folate plays a role in immune function allowing rapid reproduction of immune cells.

Synthesis of Neurotransmitters

Folate is involved in the synthesis of neurotransmitters like serotonin, dopamine, and norepinephrine, which are important for mood regulation and overall neurological function. There is a prescription drug, Deplin, that is just MTHF in high doses, which is FDA approved for depression.

The word “folate” comes from “foliage” because it is found in leaves. Common dietary sources of folate include leafy green vegetables (such as spinach and kale), broccoli, legumes (like lentils and chickpeas), whole grains, citrus fruits, and liver.

To ensure adequate folate intake, it is sometimes recommended that certain populations, such as pregnant women and individuals with specific medical conditions, take folic acid supplements. The amount is about 1,000 micrograms (1mg) per day. Taking extra folate can mask a vitamin B12 deficiency so it is a good idea to take a vitamin B12 supplement as well.

Those who have MTHFR deficiency may need to take 5 to 15mg of methylfolate daily.

Vitamin B-12

Cobalamin is the most complex of all the vitamins. Plants or animals cannot make this huge molecule. Only some archaea and bacteria can make it. Primarily, it comes from the bacteria in intestines of ruminant animals like sheep, goats, and cattle. So, meat and milk from these animals contain cobalamin. Fish is also a good source of vitamin B12.

The digestion and absorption of vitamin B12 is complex. In the stomach, acid and enzymes break down the proteins that bind B12 to release it. Then, a protein made in the stomach called intrinsic factor must bind to it to protect it from digestion. Then the B12 bound to intrinsic factor must go all the way to the end of the small intestine where it can be actively brought into the blood stream. If any of these factors are not in place, there is little absorption of cobalamin, so deficiencies are more common than with other B-vitamins.[7] Those who have had stomach or intestinal surgery probably don’t absorb much of it. There is very little passive absorption of this huge molecule, so people who don’t absorb it need very large oral doses, or shots.[8] Since a small percentage absorbed through the intestines is passive, mega doses, one to five milligrams of vitamin B12 can fill the need.

Since plants don’t make vitamin B12 it is common for people who eat vegan diets to be deficient in vitamin B12. It used to be that crops fertilized with the dung of ruminant animals added vitamin B12 to the plants. However, now that chemical fertilizers are used instead, people who avoid animal products need to supplement.

The liver can store up to five years’ worth of vitamin B12.[9] Recycled through the bile, excreted into the intestines, the end of the small intestine reabsorbs it.

Energy

Vitamin B-12 is essential for energy production in the mitochondria.

Red blood cells

Vitamin B12 is necessary for cell division, and since the bone marrow needs to make 2.4 million red blood cells every second,[10] vitamin B12 prevents anemia.[11]

Nerves

Vitamin B-12 is important for the synthesis of myelin, the insulation of nerve fibers. Without cobalamin the wires that connect nerve cells get crossed – like having a short in the wiring of your computer. Even if the cells are fine, they can’t talk to each other.

Methylation

Cobalamin works together with MTHF for methylation. Cobalamin helps make the methylfolate into MTHF to activate it.

Skin, Hair, and Nails

Those cells that are constantly growing, such as hair, skin, and nails, need a constant supply of vitamin B12.

Foods containing vitamin B12 include meat, clams, liver, fish, poultry, eggs, and dairy products.[12] While a well-balanced diet can provide sufficient B-12 for most people, certain individuals may benefit significantly from vitamin B-12 supplementation. These include anyone using antacids or acid blockers, such as omeprazole, or have had surgery of the stomach or the end of the small intestine.

Transdermal creams or patches probably offer little benefit. Sublingual vitamin B12 is mostly absorbed in the intestines. The two ways to get extra vitamin B12 is by high doses, 1-5mg, or injections. Those who cannot absorb vitamin B12 due to inflammatory bowel diseases or stomach problems, should get injections of about 1mg per month.

SUPPLEMENTING B-VITAMINS

Most of the B-vitamins do not require supplementation and ideally should come from food. There is no benefit to taking large doses of B-vitamins every day. Most of them are not toxic in large amounts, but they are associated with a shorter lifespan, except for two. Those who have higher levels of vitamin B1 and B6 are associated with a longer life.[13] But remember, association is not causation. One good example is the association of vitamin B12 and mortality. One study in older adults shows a possible increased risk of death with higher levels of cobalamin in the blood.[14]

Looking at the blue graph of everyone, the light blue, blue shaded area is the 95% confidence interval, meaning this is where 95% of the people fall. The very wide areas indicate that there is little direct correlation, nevertheless, there is a trend toward a higher death rate, and not lower. The other thing to consider is that there is an optimal level, and more is not better. The optimum is to have a blood level of between 400 to 500. The point is, that for almost every nutrient, you can get too much.

Now, considering that, what is the best way to supplement B-vitamins? For most people, a weekly dose of a supplement will keep the levels adequate and prevent excess.

B VITAMIN RECOMMENDATIONS

• Ideally, get your B-vitamins from food by eating whole foods, fresh fruit, vegetables, green leaves, beans, peas, lentils, whole grains, and avoid processed foods.
• Everyone should take extra vitamin B3, Niacin, in the form of Niacinamide, 1,000mg once per week.
• Everyone should take a B-complex, B-100, once per week. If you exercise a lot, you should take it twice per week.[15]
• If you are vegan or vegetarian, take vitamin B12 1,000mcg (1mg) once per week.
• If you have MTHFR deficiency take methylfolate (5-methylfolate, folinic acid, or MTHF) about 10mg per day.
• Other genetic issues: some people have enzyme weaknesses and find they need daily B-vitamins. Those who have enzyme abnormalities may need extra B-vitamins that are cofactors for those enzymes. How do you know? Trial-and-error, or testing. Some will try various B-vitamins to see how it affects their function. You can also do metabolic testing.

 

 

 

 

Sources:

[1] Most of this B-vitamin information is found in detail on the website of the Linus Pauling Institute:

https://lpi.oregonstate.edu/mic/vitamins/

[2] https://www.wonderlabs.com/blog/whatever-happened-to-vitamins-b4-b8-b10-and-b11

[3] https://lpi.oregonstate.edu/mic/vitamins/vitamin-B6

[4] https://pubmed.ncbi.nlm.nih.gov/15189115/

[5] https://pubmed.ncbi.nlm.nih.gov/31634773/

[6] https://www.researchgate.net/figure/Homocysteine-folate-and-vitamin-B-12-metabolism_fig1_290816945

[7] https://web.archive.org/web/20211008103749/https://ods.od.nih.gov/factsheets/VitaminB12-HealthProfessional/

[8] https://www.drweil.com/vitamins-supplements-herbs/supplements-remedies/can-vitamin-patches-benefit-health/

[9] https://en.wikipedia.org/wiki/Vitamin_B12#cite_note-Ods-2

[10] https://en.wikipedia.org/wiki/Red_blood_cell

[11] https://pubmed.ncbi.nlm.nih.gov/15189115/

[12] https://ods.od.nih.gov/factsheets/VitaminB12-HealthProfessional/

[13] Clin Nutr. 2012 Apr;31(2):191-8. doi: 10.1016/j.clnu.2011.10.010. Epub 2011 Nov 8.

Prediction of all-cause mortality by B group vitamin status in the elderly

Yi-Chen Huang 1, Meei-Shyuan Lee, Mark L Wahlqvist

[14] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8447618/

[15] https://pubmed.ncbi.nlm.nih.gov/10919966/