-part of Vit. B complex

-water soluble

-stable in most cooking

1. carboxylation/decarboxylation rxns

2. synthesis of fatty acids

3. deamination of certain amino acids

-can induce by feeding large amount of raw egg white (b/c protein AVIDIN binds biotin making it unavailable)

-infants w/ rare inborn errors of metabolism, lack fxnal biotin

-membrane structure and fxn (LECITHIN)

-lipoprotein transport

-SPHINGOMYELIN: nerve fxn and lipid metabolism -donor of 3 methyl groups

Avg diet= 500-900 mg

egg yolk, liver, legumes, human milk

High Doses (10-16 g/day)

-fishy body odor, vomiting, increase sweating

-alpha tocopherol only form maintained in body (blood and tissue)

-loss during cooking and high heat

-tocopherols & tocotrienols

-antioxidant (crucial in lungs--> RBC's carrying oxygen)

-protects unsaturated fats in tissues against oxidation

-normal nerve & immune fxn in elderly

-important for lipids in Cell Membrane

-decr. risk for CVD by decr. formation of clots

-classic symptoms in premature infants b/c transfer from mother to infant happens in last few weeks of pregnancy

-infants: RBC's rupture--> anemia

-adults: loss of muscle coord. reflexes, loss of vision/speech -associated w/ dz. causing malabsorption of fat

-absorbed in intestine during delivery to liver

-after absorption, vit. E will be in chylomicrons -storage in adipose tissue, liver, and muscle

-digestion of D3 in liver-->blood-->kidney

-incr. Ca and P in intestine

-incr. bone resorption in bones

-incr. Ca reabsorption in kidney

-incr. dehydrocholesterol in skin

-transcription of genes= Ca transport protein in intestine

1) activates hydroxylase in kidney to incr. production of D3

2) acts on bone to incr. resorption

3) incr. Ca absorp from intestine

WBC: differentiation of leukocytes

Skin: induce differentiation and inhibit proliferation of epidermal cells

Cell Culture: suppress growth of malignant cells Parathyroid: suppress secretion and production of PTH -->used for Tx of osteoporosis, renal dz., chronic liver & biliary dz.

Peptides, amines, Steroids

-Peptides=act on a specific receptor on the plasma membrane (signals communicated by intracellular signal transduction pathway)

-Steroids= easily pass thru both plasma and nuclear membranes (bind w/ Hormone Response Element in nucleus to activate transcriptional processes, signals parathyroid gland to decrease PTH when optimal levels of Ca have been reached)

1. Bowlegs

2. enlargement of ends of long bones--> knock knees

10,000-15,000 IU/day over many mts.

infants: loss of appetite, nausea, wt. loss, failure to grow

adults: nausea, vomiting, constipation, Ca deposition, emotional disturbance

Bones composed of 2 phases:

1. Inorganic=hydroxyapatite

2. Organic= 95% is collagen

Bone formed by 2 types of cells:

1. Osteoblasts=bone formation

2. Osteoclasts=bone resorption;

dissolve minerals and digest protein matrix

Bone remodeling 2 phases:

1. Bone resorption

2. Bone formation

-blood coagulation & cell metabolism

-nerve impulses and muscle contraction

-mostly in duodenum (incr. need= incr. absorp) -occurs by diffusion & active transport (need Vit. D) -unabsorbed fatty acids combine w/ Ca to form insoluble salts

-sex hormones enhance absorp. (decr. estrogen= decr. Ca absorp)

Fecal Ca: unabsorbed dietary Ca

Urinary Ca: doesn't fluctuate w/ Ca intake

-incr. Na= incr. urinary Ca loss

-minerals for bone

-metabolism of CHO, fats, proteins, etc

-cofactor in enzyme systems

-acid-base balance

-body absorbs P easier than Ca

-70% of P in diet is absorbed

1. Bone resorption= cells on bone's surface dissolve bone tissues & create cavities

2. Bone formation= cells fill the cavities w/ new bone matrix (imbalance in bone remodeling--> causes bone loss, osteoporosis, and fracture risk)

Cortical bone: compact bone in long tubular bones--> provides structural support, higher rate of remodeling

Trabecular or cancellous bone: consists of spicules of bone called trabeculae

essential to maintain Ca in narrow range normal= 9-11mg/dl

(48% ionized, 46% protein bound, 6% complex)

-PTH: incr. serum Ca and P

-Calcitonin: decr. serum Ca

Calcification of soft tissues in kidney, heart, etc that can cause organ failure & death --> regulate this by shutting off PTH and incr. calcitonin

S/Sx: constipation, vomit, abdominal pain, lethargy, mental disturbance

-90% caused by malignancy or hyper parathryroidism -10% caused by others(renal failure)

K1= phyloquinone (plant foods)

K2= menaquinone (produced by bacteria)

K3= synthetic forms (ex: menadione)

80% dietary Vit. K is absorbed

-absorption similar to that of other fat-soluble vitamins (A,E,D)

-storage limited, some in liver, adipose tissue, and muscle

Traditional Methods:

1) measure clotting time (deficient K= incr. clotting time)-->nm=11-13secs

2) determine amt. of prothrombin (not used as much as 1)

Newer Approaches:

1) primarily limited to research

2) determine Vit. K1 in serum

3) determine urinary protein (involved in blood clotting)

Def. in Ca or Vit. K lead to blood clotting--> hemorrhage CLOTTING involves prothrombin--> thrombin--> fibrinogen--> fibrin

-lack of Vit. K= osteocalcin (few or no gla groups) -decr. bone density, incr. hip fractures

Factor Xa produced by:

1) Extrinsic System= initiated by release of thromboplastin as a result of dmg to blood vessel walls and surrounding tissues

2)Intrinsic System: physical dmg to certain components within platelets causes release of thromboplastin which may interact w/ clotting proteins in blood.

-post-translational carboxylation of glutamate residues in a protein precursor of prothrombin -gamma carboxy group facilitates binding of the protein w/ Ca (which is required for every step in the clotting process)

-formation of gamma carboxy glutamate groups also essential in synthesis of Factors VII, IX, and X (active forms)

-bone formation

-all made in liver 1st in inactive form and later gets converted by enzyme that requires Vit. K

-These proteins known as gla proteins

-Excreted in Urine

-made in liver

-contain gamma carboxy glutamate groups

-involves in inhibition of clotting

-gla protein made by osteocytes

-exact fxn not completely understood

-involved in bone calcification

incr. tendency to hemorrhage

-rare in adults b/c widely distributed in food & can be synthesized by intestinal bacteria

-newborns at risk of hemorrhage due to lack of Vit. K -newborns tend to have low serum vit. K and have minimal stores

-not transported across placenta efficiently

-vit. K shot given shortly after birth to prevent hemorrhage

-pt. w/ fat malabsorption

-pt. w/ bile salt deficiency

-use of certain oral antibiotics

use of drugs that act as antagonists

-coumadin warfarin Na

-inhibit Vit. K redox cycle

-Dicumarol