Major Minerals and Bone Health

Question 1

There are three factors that affect the bioavailability of minerals. What are they?

Answer 1

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 inhibit absorption of iron)

Question 2

Where do we find calcium in our diet?

Answer 2

Dairy
Canned fish
greens
nuts

Question 3

Calcium can be absorbed passively or actively.

Explain how each is absorbed in each form and which is better for higher or smaller intakes of calcium

Answer 3

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)

Question 4

Why is Vit D important for calcium absorption? (Two reasons)

Answer 4

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

Question 5

What are the roles of calcium? (6)

Answer 5

Bone health
Nerve transmission
Muscle contraction
Blood coagulation
Hormone release
Maintenance of BP

Question 6

How is Calcium homeostasis sustained when there is LOW blood Calcium? (4 steps)

Answer 6

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

Question 7

How is Calcium homeostasis sustained when there is HIGH blood Calcium? (2 steps)

Answer 7

High blood Ca causes thyroid gland to release calcitonin

Calcitonin inhibs calcium release from bone

Question 8

How does increase prebiotics in milk affect Calcium bioavailability?

Answer 8

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

Question 9

Where can we find phosphorus in our diet?

Answer 9

Available in many foods such as protein rich foods includes

meat

poultry

fish

dairy products

Question 10

What is the function of phosphorus? (4)

Answer 10

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

Question 11

Does phosphorus need vit D to be absorbed?

Answer 11

Vit D is involved in active transport for P

However P can be absorbed w/o aid of Vit D

Question 12

Where is Magnesium found in our diet?

Answer 12

In less processed healthier foods

Beans
Seeds
nuts
spinach
kiwi
grains

Question 13

What is the function of Mg? (6)

Answer 13

1. Maintenance of bones
2. Cofactor for enzymes
3. Involved in E metabolism and Na K pump
4. Vital for dividing cells
5. Creating circumstances for maintaining proper BP
6. Synthesis of proteins, nucleic acids, fats DNA and RNA

Question 14

Where is sulphur found in the diet?

Answer 14

Obtained in dietary protein and food preservatives

Question 15

What is the recommended intake for sulphur?

Answer 15

There is none

As long as you are getting adequate protein then you should be getting enough sulphur

Question 16

To prevent kidney stones should you reduce your calcium intake?

Answer 16

NO

Reduced calcium intake encourages greater oxalate absorption

Question 17

Ways to prevent Kidney stones?

Answer 17

Increase fruit and vegetable

Drink more water

Try to create and follow the DASH diet

Use more plant proteins rather than animal proteins