vitamin D lecture

vitamin D basics

NOT a vitamin

fat soluble

present in skin and fat tissue

vitamin D breakdown

UV breaks ring steroid alcohol in skin forms cholecalciferol

turns to 25-hydroxy vitamin D by liver

turns to 1, 25-dihydroxy D (active, calcitrol)

attaches to DNA gene receptors of cell’s nucleus

vitamin D function

regulates release of neurotransmitters (MENTAL HEALTH)

dietary absorption of calcium and phosphorus(bone health)

activates cell growth/death genes

vitamin D deficiency

rickets, infection, autoimmune, cancers

types of vitamin D

D2: plants

D3: skin from sunlight, ingested animal sources

vitamin D specimen requirements

serum must be separated within 72 hours

refrigerated up to 12 days- frozen if longer

vitamin D reference ranges

def.= <13ng/ml

insufficent= 13-29ng/ml

optimal= 30-96 ng/ml

potential intoxication= >96ng/ml

vitamin D potential intoxication symptoms

vomiting, heart arrythmias, constipation, weight loss, kidney failure, calcification of arteries

sources of vitamin D

sunlight, oily fish, cereal milk, orange juice, cereal, milk

testing

25-OH vitamin D

chemiluminescent assay (competitive)

quantitative

RLUs

indirect relationship btwn Vit D in sample and amount of RLU

deficiency symptoms

fatigue, shortness of breath, poor concentration, arthritis, and depression

unit conversion

Y nmol/L x 0.40= Z ng/ml

Z ng/ml x 2.5= Y nmol/L