Vitamin & Minerals Flashcards
Vitamins are chemically unrelated organic compounds & cannot be synthesised by the human body. It is divided into
Water soluble vitamins
Fat soluble vitamins
Water soluble vitamins are
Precursors of coenzymes (+ Vit K)
Divided into non-B complex and B complex
Non-B complex water soluble vitamin is
Ascorbic acid/vit C
B complex water soluble vitamins are
energy releasing
Thiamine/b1
Riboflavin/b2
Niacin/b3
Biotin/b7
Pantothenic acid
hematopoietic
Folic acid
Vit b12
other
Pyridoxine/b6
Pyridoxal
Pyridoxamine
Fat soluble vitamins are
ADEK
A (retinol, beta-carotenes)
D (cholecalciferol)
E(tocopherol)
K (phylloquines, menaquinones)
Deficiency of Thiamine/B1
(Thiamine pyrophosphate TPP is coenzyme)
Decreased ATP
Impaired cellular function
beri-beri
1. Adult beri-beri
a) dry: non-specific peripheral neuropathy
b) wet: oedema due to cardiac dysfunction
2. Infantile beri-beri: in nursing infants whose mothers are deficient
Deficiency in riboflavin/B2
Biologically active forms:
Flavin mononucleotide (FMN)
Flavin adenine dinucleotide (FAD)
Dermatitis
Cheilosis
Glossitis
Deficiency in niacin/b3
Biologically active forms:
Nicotinamide adenine dinucleotide (NAD)
Nicotinamide adenine dinucleotide phosphate (NADP)
Pellagra:
3Ds- Dermatitis, Diarrhea, Dementia
Deficiency in Pantothenate/b5
-a component of CoA
Dermatitis
Alopecia/hair loss
Adrenal insufficency
Deficiency in Pyridoxine/b6
Precursors of active coenzyme, pyridoxal phosphate (PLP) for many enzymes
Clinical indications:
isoniazid-treat TB, can induce B6 deficiency by forming an inactive derivative with pyridoxal phosphate (PLP)
Deficiency: angular cheilosis嘴角破, glossitis, convulsion & hyperirritability, peripheral neuropathy
Deficiency in Biotin/b7
Does not occur naturally
Dermatitis, glossitis, loss of appetite, nausea
Deficiency in folic acid/folate/b9
A key role in one-carbon metabolism
Most common vitamin deficiency among pregnant women and alcoholics
source: leafy dark green veg
Types of nutritional anemias
(Caused by inadequate intake of one/more essential nutrients, classify according to the size of the RBCs or mean corpuscular volume MCV)
Microcytic (MCV<80)
-deficiency in iron, pyridoxine, ascorbate
Normocytic (MCV=80-100)
-protein- energy malnutrition
Macrocyclic/megaloblastic anaemias(MCV>100):
-deficiency in vitamin B12 & b9 folate
-due to low purine and TMP thymidine monophosphate
-inability of RBC precursors/megaloblast to make DNA
-cannot cell divide
-accumulation of large immature megaloblast in bone marrow and blood
Deficiency in B9 in pregnancy
Neural tube defects in foetus
*need to give folic acid supplementation before conception and during the 1st trimester
*0.4mg/day for all women of childbearing age
Deficiency in cobalamin/b12
Neurological manifestations
pernicious anemia:autoimmune destruction of gastric parietal cells that are responsible for the synthesis of intrinsic factor
source: only found in animals, not present in plants
Absorption of cobalamin/b12
B12 is released from food in the acidic environment of stomach.
Malabsorption of vit b12 in elderly is due to reduced secretion of gastric acid.
Functions of ascorbic acid/vit C
-reducing agent
-coenzymes in hydroxylation (proline & lysine) of collagen [maintenance of normal connective tissue & wound healing]
-reduces ferric iron to ferrous form->facilitate the absorption of dietary iron from intestine
Deficiency in ascorbic acid/vit C
Scurvy: sore spongy gum, loose teeth, haemorrhage, swollen joints, fatigue, impaired wound healing, microcytic anemia caused by decreased absorption of iron
Antioxidants such as ? can decrease incidence of some chronic diseases such as coronary heart disease and certain cancers
Vit C
Vit E
Beta-carotene
Functions of vit A
Retinoids- vision, reproduction, growth, maintenance of epithelial tissues, immune function
Structures in Vit A
retinol: in animal foods as as retinyl ester
retinal: aldehyde, from [O] of retinol ->vision
retinoic acid:acid, from [O] of retinal ->most actions of retinoids except vision
beta-carotene:in plants, can be split to make two retinal
Sources of vit A
Preformed vit A: Egg yolk, butter
Precursors of vit A (carotene): yellow, orange, dark green veg and fruits
Deficiency in Vit A
1.Night blindness
2.Infectious diseases
3.Blindness: xerophthalmia(dryness of conjunctiva & cornea) ->untreated will from cornea ulceration, formation of opaque scar tissue and blindness
4.keratinisation: rough, dry, scaly skin
5.toxicity/ hypervitaminosis A :due to consumption of excessive amount of b-carotene/preformed vit A
6.birth defects like teratogenic in fetus
Sources of vit D
Vit D has hormone-like function
Sources:
Endogenous
Diet- fatty fish, liver, egg yolk
Main functions of vit D
Increase uptake of Ca in intestine
Minimise loss of Ca by kidney by increase re absorption
Stimulate resorption/ demineralisation of bone
Deficiency in Vit D
Rickets in children
Osteomalacia in adults
Toxicity of vit D seen with use of supplements
Hypercalcemia:
Deposition of Ca in many organs like arteries and kidneys
Function of vit E/alpha-tocopherol
Antioxidant
Sources of vit E/ alpha-tocopherol
Veg oil
Liver
Eggs
Vit K serves as
-Coenzymes in post translations modification of many protein
-hepatic synthesis of blood clotting proteins, prothrombin (factor II), factor VII, IX, X
Sources of vit K
Cabbage, kale, spinach, egg yolk, liver
Extensive synthesis by bac in gut
Minerals are divided into
Major elements/ Macrominerals: daily requirement >100mg
Trace elements : <100mg/day
Macrominerals are
Calcium
Phosphorous
Magnesium
Sodium
Potassium
Chloride
Sulphur
Ca Mei NaKCl PS
Trace elements are
Iron
Zinc
Chromium
Copper
Iodine
Manganese
Selenium
Molybdenum
Fluorise
