Water Soluble Vitamins

From scholar RX readings on water-soluble and fat-soluble vitamins

Role of Vitamin C

• Antioxidant

• Collagen synthesis

• Absorption of iron

Role of Folate (folic acid , Vitamin B9)

• Neural development

• Red blood cell (RBC) formation

Role of Vitamin B12

• Blood RBC development

• Central nervous system (CNS) maintenance

Role of Vitamins B1, B2, B3, B5, B6, B7

• Metabolism: energy production and digestion

What are the water-soluble vitamins?

Vitamin C and B complex (B1, B2, B3, B5, B6, B7, B9, B12)

What happens to most water-soluble vitamins?

• They are not stored in the body and are eliminated in the urine.

• They are absorbed easily as well as excreted easily if their blood concentrations increase too much.

• Exceptions: Folate (B9) and B12

How often do water-soluble vitamins need to be consumed for proper body function?

daily

Vitamin B1

Thiamin

Vitamin B2

Riboflavin

Vitamin B3

Niacin

Vitamin B5

Pantothenic acid

Vitamin B6

Pyridoxine

Vitamin B7

Biotin

Vitamin B9

Folate

Vitamin B12

Cobalamin

What do B vitamins do?

• make the most out of carbohydrates, fats, and proteins obtained from the diet

• help synthesize important molecules, break down food to capture energy as ATP, or assist certain reaction pathways in reaching their next step

How are the B vitamins involved in metabolic reactions?

• acting as coenzymes (type of cofactor) to help enzymes in anabolic (synthesis), catabolic (breakdown), and intermediate reactions

Cofactor

• Nonprotein molecules required for the optimum function of enzyme

Vitamin B6 (pyridoxine) in Metabolic reactions

• when consumed, is converted to pyridoxal phosphate (PLP), which is cofactor for transamination reactions and required for both synthesis and breakdown of amino acids

• B6 in active form of PLP is essential for reactions that synthesize heme, several neurotransmitters, and even vitamin B3 (niacin)

Folate (Vitamin B9) in Metabolic Reactions

• Converted to its active form of tetrahydrofolic acid

  • important for synthesis of nitrogenous bases that become incorporated into RNA and DNA

• help cells multiply

Vitamin B12 (cobalamin) in Metabolic Reactions

• essential to the process of DNA synthesis

• help cells multiply

Thiamin (B1), Riboflavin (B2), Niacin (B3), Pantothenic acid (B5), and Biotin (B7) in Metabolic Reactions

• Participate in the release of energy from carbohydrate, fat, and protein

• B vitamins in their active forms either directly or indirectly assist in the progression of metabolic pathways that ultimately end with the electron transport chain generating ATP

Constituent of Cofactor for B1 (thiamin)

Thiamine pyrophosphate (TPP)

Constituent of Cofactor for B2 (riboflavin)

Flavin mononucleotide (FMN), flavin adenine dinucleotide (FAD)

Constituent of Cofactor for B3 (niacin)

Nicotinamide adenine dinucleotide (NAD+), nicotinamide adenine

dinucleotide phosphate (NADP+)

Constituent of Cofactor for B5 (pantothenic acid)

Coenzyme A (CoA)

Constituent of Cofactor for B6 (pyridoxine)

Pyridoxal Phosphate (PLP)

Constituent of Cofactor for B7 (biotin)

Biotin

Constituent of Cofactor for B12 (Cobalamin)

Cobalamin

Constituent of Cofactor for Folate (Folic acid, B9)

Folate

Constituent of Cofactor for Vitamin C

Ascorbic Acid

Where is B12 mainly sound?

Mainly in animal products but also Brewer’s yeast is also a rich source

Where are vitamin B deficiencies especially likely?

In regions where the staple food is made from refined grains

What foods drastically reduce vitamin B deficiency?

Fortifying grain products such as breads and cereals with vitamin B

What are grain products most commonly fortified with?

Vitamins B1, B2, and B3, as well as minerals such as iron and calcium

Maternal Folate Deficiency

• Causes neural tube defects in the embryonic period

What is an important cause of water-soluble vitamin deficiency in developed countries?

Alcoholism

Beriberi

Thiamin (B1) deficiency

Symptoms of Thiamin B1 Deficiency

• Causes degeneration of peripheral nerves, thalamus, mammillary bodies, and cerebellum

• heart may become dilated as the muscle fibers become swollen, fragmented, and vacuolated

Dry Beriberi

• the peripheral neurological complications of thiamin deficiency

• results in symmetrical, bilateral stocking and glove distribution of peripheral neuropathy

• in extreme cases, associated with Wernicke-Korsaoff syndrome

Wet Beriberi

• myocardial complications of thiamin deficiency

Vitamin B2 (Ribofoavin) Function

• ATP Production (Energy)

  • TCA cycle

  • Use of fatty acids for energy

• Synthesis or Activation of Vitamins

  • Vitamin A, folate, niacin, vitamin B6, vitamin K

• Neurotransmitter Metabolism

  • Dopamine, Norepinephrine

• Involved in oxidation and reduction reactions (Glutathione reductase - for removal of reactive oxygen species

Symptoms of Vitamin B2 (Ribofoavin) Deficiency

• Inflammation of membranes

  • Glossitis

  • Chellosis

  • Seborrheic Dermatitis

  • Itchy and red eyes

Symptoms of Niacin (B3) Deficiency

• Causes Pellagra

• Symptoms manifest in skin, mucous membranes, gastrointestinal (GI) tract and CNS

• Dermatitis

  • occurs in areas of greatest sunlight exposure with hyperpigmentation that initially resembles a sunburn on the limbs and like a collar around the neck, in the C3 and C4 dermatones → Casal necklace

• GI manifestations

  • Include nausea, vomiting, epigastric discomfort, loss of appetite, and diarrhea (generally water but can contain mucus or blood

• CNS manifestations

  • progressive and start as nonspecific symptoms

    • irritability and confusion; patients may even present with ataxia and hallucinations

• w/o treatment → pellagra advances in the CNS, bringing patient to a comatose state, which is followed by death

Treatment of Niacin (B3) Deficiency

Niacin (B3) replacement and a high-protein diet

Four Ds of Pellagra

• Diarrhea

• Dermatitis

• Dementia

• Death

Who is Pellagra common among?

• Poor people in the US whose diets consisted mostly of corn, molasses, and salt

Cause of Niacin (B3) Deficiency

• Problems that affect the absorption of niacin or tryptophan

  • In GI tract → alcholosim

  • Hartnup disease and carcinoid syndrome

    • both reduce the amount of tryptophan available to derive niacin

  • Pellagra → adverse effect of prolonged treatment with tuberculosis drug isoniazid

    • long-term use of isoniazid depletes vitamin B6 (pyridoxine) stores, which are required to synthesize niacin

    • patients taking isoniazid receive supplemental vitamin B6

Hartnup Disease

• Autosomal recessive

• can present with pellagra-like symptoms due to decreased absorption of dietary tryptophan in the gut

• intestinal and renal transport of neutral amino acids (alanine, serine, threonine, valine, leucine, isoleucine, histidine, glutamine, asparagine, phenylalanine, tyrosine, and tryptophan) is defective

Carcinoid Syndrome

• Can be at fault of niacin deficiency due to increased tryptophan metabolism

Sources of Vitamin B7 (Biotin)

• Foods that contain the most biotin: organ meets, eggs, fish, meat, seeds, nuts, and certain vegetables (such as sweet potatotes)

• Produced by GI bacteria

Functions of Vitamin B7 (Biotin)

• Co-enzyme that adds CO2 to compounds

• Required for metabolism of carbohydrates, fats, and proteins

• ABC Carboxylates ATP, Biotin, CO2

Cause of Vitamin B7 (Biotin)

• Biotinidase enzyme deficiency

• Excessive consumption (>12) of raw eggs (avidin)

Symptoms of Vitamin B7 (Biotin)

• Skin rash, hair loss, convulsions, and impaired growth

Symptoms of Vitamin B12 Deficiencies

• megaloblastic anemia

• neurological symptoms such as numbness or tingling

• possible irreversible nerve damage if prolonged and not treated appropriately

• elevated homocysteine levels and elevated methylmalonic acid levels

Folate (B9) Deficiencies

• megaloblastic anemia

• elevated homocysteine levels

Most Common Cause of Vitamin B12 Deficiency

• Pernicious Anemia

  • autoimmune condition affects absorption of B12 in the GI tract

    • dietary B2 is bound to R-binders (haptocorrin) to protect it from the acidic environment

    • B2 is released from R-binders once it reaches the ileum, at which point B2 then binds to intrinsic factor (IF)

    • B12-IF complexes are then absorbed into the body

Vitamin B6 Toxicity

• symptoms were seen in those who took more than 2g of vitamin B6 daily ( 20 times the current UL of 100 mg) for 2 months or longer

• 1st symptom: numb feet

• then loss of sensation in the hands, and eventually unable to walk

Function of Vitamin C

• helping to form collagen → important protein of connective tissues

  • aids in the hydroxylation of collagen molecules by acting as a coenzyme to lysyl-hydroxylase and prolyl-hydroxylase

• important antioxidant

• involved in metabolism of several amino acids

• Involved in absorption of iron

  • prevention of formation of unabsorbable iron compounds and reduction of ferric iron to ferrous iron

• Norepinephrine synthesis

  • Dopamine to norepinephrine by dopamine β-hydroxylase

• Antihistamine

• Cancer Prevention

What can increase the absorption of iron in foods?

• Eating foods containing vitamin C and foods containing iron at the same meal

• Can double or even triple the absorption

Symptoms of Vitamin C Deficiency

• Gums bleed easily

• Capillaries under the skin break spontaneously, producing pinpoint hemorrhages

Cause of Scurvey

Vitamin C Deficiency

• develops after weeks or months of vitamin C depletion

Symptoms of Scurvy

• Muscles including heart muscle may degenerate

• Skin becomes rough, brown, scaly, and dry

• Wounds fail to heal → scar tissue doesn’t form without collagen

• Bone rebuilding falters and ends of long bones become softened, malformed, and painful, leading to potential fractures

• Teeth become loose in the jawbone and fall out

• Anemia and infections are common

• Sudden death is likely → massive bleeding into joints and body cavities

• bleeding gums and pinpoint hemorrhages

Vitamin C Toxicity

• tolerable upper intake level for vitamin C is 2000 mg/d

• nausea, abdominal cramps, and diarrhea

Food Source of Thiamin (B1)

• Small quantities in virtually all nutritious foods

• Concentrated in a few foods; pork is the one most commonly eaten

Food Source of Riboflavin (B2)

• Milk, milk products

• Enriched breads, cereals, other grain products

• Green vegetables: broccoli, turnip greens, asparagus, spinach

• Meats

Food Source of Niacin (B3)

• Meat, poultry, fish

• Legumes

• Enriched whole grains

• Some vegetables: mushrooms, asparagus, potatoes

Food Source of Pyridoxine (B6)

• Meat, poultry, fish

• Potatoes, a few other vegetables

• Some fruits

• Lost when foods are heated

Food Source of Folate (B9)

• Liver

• Legumes

• Some vegetables: beets, leafy green vegetables

• Some fruits: oranges, cantaloupe

• Enriched whole grains

• heat and oxidation during cooking and storage can destroy up

  to half of the vitamin in foods

Food Source of Cobalamin (B12)

• Produced by microorganisms

• Mainly obtained in diet via animal-derived products, eg, meat, dairy products

• Easily supplemented

• vegans who do not eat animal products are at risk of deficiency

  without appropriate supplementation

Food Source of Vitamin C

• Some fruits: citrus fruits, cantaloupe, strawberries

• Some vegetables: broccoli, Brussels sprouts, potatoes