Water Soluble Vitamins Flashcards
Digesting and Absorbing water soluble vitamins
WSVs are hydrolyzed in the stomach and then absorbed in the upper part of the SI (other than B12, which is in the ileum), and then is sent into portal vein, and then transported to the liver where they are either stored (B12) or go straight into systemic circulation.
- Any excess WSVs are excreted in the urine.
What is the role of most vitamins?
They function as components of specific coenzymes.
B vitamin mnemonic
The Rhythm Nearly Proved Fully Contagious
What’s its of foods haveThiamine ?
Whole grain products
What vitamin will often be deficient in alcoholics?
Thiamine
Functions of Thaimine
Acts in the TCA cycle to activate pyruvate dehydrogenase, alpha ketoglutarate dehydrogenase, and branched-chain alpha-ketoacid dehydrogenase. Essential for normal functioning of heart, muscles, and nervous system.
Symptoms of B1 deficiency
Beriberi
- general symptoms - poor appetite, irritability, apathy, confusion, and weight loss
Beriberi
2 types, Both due to a B1 deficiency, wet and dry:
Wet - edema due to cardiovascular problems
Dry - muscle wasting, neurological disorders
What foods have B2 (riboflavin) in them?
Milk products, liver
WHat form of riboflavin will we see in the body?
FAD (flavin adenine dinucleotide) mostly but some FMN (flavin mononucleotide)
Functions of FADH2/riboflavin/B2
They act as prosthetic groups in oxidative phosphorylation and the TCA cycle. HEavily involved in Redox reactions.
Deficiency of B2
Inflammation of membranes –> sore throat, cheilosis, glossitis, stomatitis, seborrheic dermatitis, bloodshot eyes, sensitivity to light.
- cheilosis is cracks at corners of mouth
- stomatitis - inflammation of mouth and lips.
Seborrheic dermatitis - causes flaky, white to yellowish scales on oily areas such as the scalp, face, or inside of ear.
Where can you find B3 (niacin)
Protein rich foods
What form of B3 will we mostly see in the body?
Nicotinamide, NAD, NADP.
- can also be made from tryptophan in the body..
Function of B3
Redox reactions
Deficiency of B3
Leads to 4Ds called pellagra - diarrhea, dermatitis, dementia, death.
- can be seen in alcoholics and in people with corn-asked diets.
Mnemonic - 3 leads to 4
Toxicity from B3
Often used to lower LDL.
- you can get flushing and itching
Bioavailability - factors that influence it
Amount actually absorbed and used in the body, which differs based on: efficiency of digestion and transit time in the GI tract, method of food prep, previous nutrient intake, source of nutrient, and other foods consumed at the same time.
Where can we Find B6 (pyridoxine))
Protein rich foods and starchy vegetables.
Forms of B6
Pyridoxal, pyridoxine, pyridoxmine –> pyridoxal phosphate
- stored exclusively in muscle tissue.
Function of B6
AA metabolism, urea metabolism, synthesis of heme, and converts tryptophan to niacin (B3), synthesis of neurotransmitters.
B6 deficiency
Very rare - can occur if women feeds a baby a formula low in B6, could happen in alcoholics, could happen due to oral contraceptives
- most importantly, it can happen due to takin isoniazid, which is used to treat Tb as well as penicillamine which treats Rheumatoid arthritis.
Symptoms - cheilosis, glossitis, dermatitis, depression, confusion
B6 toxicity
Nerve degeneration
Where can we find B9
Dark leafy vegetables
Function of B9
Synthesis of DNA and RNA
- also regenerates methionine from homocysteine
B9 deficiency
Causes macrocytic anemia, weakness, fatigue, headache, palpitations, and SOB
- also associated with heart disease due to increased homocysteine.
What can occur if a pregnant woman doesn’t take folate supplements?
Neural tube defects such as spina bifida
Where can we find B12 (cobalamin)
Foods of animal origin
Digestion of B12
1) salivary glands produce R
2) R travels to the stomach with B12, which is still bound to protein
3) B12 is then released from the protein and binds to R to protest it from the acidic environment.
4) IF is released from parietal cells in the stomach and moves to the SI with the R/B12 complex.
5) pancreatic enzymes cleave R-protein allowing B12 to bind to IF.
6) at the ileum B12 is internalized because there are IF receptors there.
Function of B12
Regeneration of methionine, synthesis of DNA and RNA.
- helps maintain nerve cells
- works in concert with Folate (B9).
B12 deficiency
Can occur due to vegan diet or decreased IF, decreased R, decreased gastric acid, or removal of terminal ileum.
pernicious anemia - where you have autoimmune inactivating of IF causing B12 deficiency
Symptoms - megaloblastic anemia, nerve damage (tingling in extremities), painful swollen tongue.
Biotin (B7)
Deficiency?
Coenzyme for ABC carboxylase. A = ATP , B = biotin , C = carbon dioxide
- deficiency will cause hair loss, rash, convulsions, impaired growth.
- – often occurs due to biotinidase enzyme deficiency or excessive egg consumption
Pantothenic acid (B5) Sources, form, functions
Sources - meat, milk, veggies
Form - CoA or acyl carrier
Functions - synthesis of fatty acids, Triacylglycerol, cholesterol, and cetolcholene. Involved in synthesis of cell membrane.
Interactions among B-vitamins
- Folate and B12
- riboflavin converts B6 (pyridoxine) to PLP
- robiflavin and PLP are required to convert tryptophan into niacin
Sources of Vitamin C
Citrus fruits and some veggies
Functions of vitamin C
- Formation of collagen –> therefore it strengthens bone, blood vessels, and anchors teeth into the gums and acts in tissue repair and would healing.
- antioxidant
- synthesis of NTs
- important in fatty acid degradation
- increases bioavailability of iron.
What are the two enzymes involved in he hydroxylation reactions in collagen synthesis?
Prolyl hydroxylase
Lysyl hydroxylase
- vitamin C is a cofactor in both of these rxns.
Vitamin C deficiency
Scurvy - muscle weakness, joint pain, impaired wound healing, loose teeth, bleeding and swollen gums, bruised skin, fatigue
Vitamin C toxicity
Oxaloacetate kidney stones
