Lecture 08 - Vitamin

Lecture 08 - Vitamin - Lecture 08 Vitamin/Mineral...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Lecture 08 – Vitamin/Mineral Vitamin/mineral absorption ( introduction ) In addition to the macronutrients Some are referred to as “micronutrients”, because they are required in only trace amounts Nevertheless, their absorption from the diet is essential to health and deficiencies result in specific disease states Vitamin/mineral absorption (classes of micronutrients ) Vitamins Water soluble, e.g., vitamin C, cobalamin B12, folate Fat soluble, e.g., vitamins A,D,E and K Metals /trace elements Iron Calcium Zinc Copper Vitamin/mineral absorption (Vitamins) Vitamins are small molecules cannot be synthesized by the body (exception – Vitamin D) but which are essential to normal metabolism Vitamin D can be produced in our body with sunlight Most are co-factors for specific biochemical reactions or play other critical roles Specific uptake mechanisms are only beginning to be defined Vitamin/mineral absorption ( Vitamin C: Ascorbic acid) Derived from citrus fruits and vegetables Functions as an antioxidant , and also in hydroxylation reactions and collagen synthesis If you deficient in Vit C – scurvy disease (sailors used to suffer from) Absorption at low luminal concentrations involves sodium-coupled transport Can transport Vit C uphill since it is coupled with Na+ Passive diffusion may also occur at high concentrations/acidic pH it is an acid in the stomach where there is a low pH it can get protonated and get passively absorb across the epithelium Circulating levels regulate intestinal absorption (Vitamine homeostatsis) Where the body regulates the amount of Vit in the body Vit C transporter 1 and a Vit C cotransporter 2 Both assist in taken in Vit C Not understood how it enters the bloodstream If the Vit C raise in blood stream negative feedback to Vit C transporter(homeostatic regulation) Vitamin/mineral absorption ( Vitamin B 12 (cobalamin)) Derived from animal protein Functions in DNA synthesis and the preservation of myelin (the important compound that provide for the insulation around nerve sheets) Deficient – neuropathy (defect in nerve conduction because of the lost of myelin) Absorption involves a multistep process that includes various binding proteins in the lumen, cell membrane and circulation Absorption of dietary cobalamin delivered to the stomach It interacts with gastric/salivery products. . Parietal cells (IF – that helps with absorption)
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 4

Lecture 08 - Vitamin - Lecture 08 Vitamin/Mineral...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online