Zinc Flashcards
How is Zinc absorbed in the body?
By diffusion and carrier protein
20-33% absorbed depending on requirements
Small amounts absorbed more efficiently
What makes zinc more easily absorbed?
Leavened bread breaks phytates from zinc which helps absorption 10x
What decreases the availability of zinc?
High amounts of non heme iron impair absorption
Alcohol impairs absorption
What is metallothionein?
A binding protein which blocks’z zinc’s entry into the blood stream, acts as a mucosal block
But block is overridden by supplements
What are the function of zinc?
Metabolism:
- growth/development
- immunity
- antioxidant function
- neurological function
- reproductive function
What are the catalytic functions of zinc?
As a cofactor in over 300 enzymes
- alcohol metabolism (needed for alcohol dehydrogenase)
- cofactor for folate conjugase
What are the structural functions of zinc?
Zinc fingers
important in protein structure and cell membrane
Stabilisation of vitamins A, D, thyroid hormone
What is the regulatory role of Zinc?
Zinc protein fingers act as transcription factors to regulate gene expression
What is caused by a zinc deficiency?
- anorexia
- dermatitis
- poor wound healing
- poor development in children
- decreased immune function
What is caused by a zinc toxicity?
- anorexia
- nausea, vomiting
- decreased copper, magnesium absorption
What are good dietary sources of zinc?
- oysters
- sunflower seeds
- lamb and beef
