Major Minerals and Bone Health Flashcards
There are three factors that affect the bioavailability of minerals. What are they?
Absorption of minerals can be affect by what it is packaged with (Dietary compounds can inhib or enhance absorption)
Life stage of person may affect absorption (Ex. Pregnant folks absorb more calcium)
Absorption of minerals of same charge depends on amount of each in a meal (Ex. High Ca meal may inhib absorption of iron)
Where do we find calcium in our diet?
Diary, Canned fish, greens and nuts
Calcium can be absorbed passively or actively. Explain how each it is absorbed in each form and which is better for higher or smaller intakes of calcium
Passive: % absorbed decreases with increased ingestion (Therefore more important with high intakes)
Active: Vit D promotes expression of calcium transporter and allows more calcium to be taken in from diet (Therefore more important for smaller intakes)
Why is Vit D important for calcium absorption? (Two reasons)
Vit D allows more calcium to be taken up from diet through promotion of expression of calcium transporter
Vit D is necessary for synthesis of Ca transport proteins
What are the roles of calcium? (6)
Bone health Nerve transmission Muscle contraction Blood coagulation Hormone release Maintenance of BP
How is Calcium homeostasis sustained when there is LOW blood Calcium? (4 steps)
Low blood Ca causes parathyroid glands to release parathyroid hormone
PTH goes to kidney and increase resorption of calcium and activates Vit D
Vit D inc intestinal Ca absorption
PTH can stim Ca release from bone
How is Calcium homeostasis sustained when there is HIGH blood Calcium? (2 steps)
High blood Ca causes thyroid gland to release calcitonin
Calcitonin inhibs calcium release from bone
How does increase prebiotics in milk affect Calcium bioavailability?
Colon feeds on prebiotics and increases inulin and creates short chain FA
FA makes environment acidic which in turn allows absorption of additional calcium in large intestine
Where can we find phosphorus in our diet?
Available in many foods such as protein rich foods includes meat, poultry, fish and dairy products
What is the function of phosphorus? (4)
P needed for phospholipids in cell membranes
RNA and DNA synthesis
Formation of high energy compounds such as AP and creatine phosphate (Used by muscle for exercising)
Used as a part of signal transduction
Does phosphorus need vit D to be absorbed?
Vit D is involved in active transport for P
However P can be absorbed w/o aid of Vit D
Where is Magnesium found in our diet?
In less processed healthier foods
Beans, Seeds, nuts, spinach, kiwi, and grains
What is the function of Mg? (6)
- Maintenance of bones
- Cofactor for enzymes
- Involved in E metabolism and Na K pump
- Vital for dividing cells
- Creating circumstances for maintaining proper BP
- Synthesis of proteins, nucleic acids, fats DNA and RNA
Where is sulphur found in the diet?
Obtained in dietary protein and food preservatives
What is the recommended intake for sulphur?
There is none
As long as you are getting adequate protein then you should be getting enough sulphur
