Fat Soluble

Precursor

A (RETINOL) Carotenes (a,b,y, cryptoxanthine)

D (CALCIFEROL) Sterols

Potent Form

B-carotene

25 OH – (5X) LIVER 1, 25 OH – (10X) KIDNEYS

Storage form Absorption Transportation Metabolism

In LIVER Reqs: BILE and PANCREATIC juice via Chylomicrons as LIPOPROTEIN) Bound to RBP (target cells have RBP surface receptors) Not excreted High temp./ heat UV light

Excretion Stable in/@ Unstable in/@ Dietary forms/ Food sources Functions

E (TOCOPHEROL) Tocopherols (a,b,y,d) tocotrienols

Inefficient (20-30%)

K (ani-hemorrhagic factor/ coagulation vitamin) K1 (phylloquinone) H20 sol. – grrenplants K2 (menaquinone) H20 sol. – prod. bacteria syn. K3 (menadione) fat sol. – lacks long side chain of natural vitamin LIVER Reqs: BILE and PANCREATIC juice via CHYLOMICRONS/LIPOPROTEIN

Reqs: UV light = cholecalciferol

Retinyl Esters (animals) B-carotene (plants) 1. RETINOIC ACID – growth and maintenance of “epith. tissues”

7-DHC (animals) Ergosterol (plants) 1. Absorption of Ca2+ via CALBINDIN (Ca2+ binding protein) in brush border

2. 11-cis RETINOL – constituent of “rhodopsin”; mediator in visual process

2. Stimulate PHOSPHATE transport system

Heat and acids Alkali, UV, O2 Rancid fats, Lead and iron

Resistant to heat

1. ANTI-OXIDANT (PUFA and Vit. A)

1. COFACTOR - for “carboxylase” in LIVER (Glu  Gla)

2. FREE RADICAL SCAVENGER –protects cellular membrane integrity

2. good CHELATOR of Ca2+ for blood coagulation (factors 2, 7,9 and 10  more COO-)

3. Bone Resorption Deficiencies

4. Renal reabsorption of Ca2+ and PO4RICKETS a. bowlegs/knock-knees b. pigeon breast c. ‘rakitic roasary’ OSTEOMALACIA a. rheumatic pain b. waddling gait c. tetany - pronounced softening and pliability of “pelvic bones”

Excess

Abnormal bleeding d/t irrational use of ANTIBIOTICS a. lipid malabsorption b. destruction of intestinal flora HIGH RISK: new born and premature babies