Chapter 12: Nutrients Involved in Bone Health

Question 1

What’re the two types of bone? What’re their functions/where can they be found?

Answer 1

1) cortical bone: More compact bone that makes up the outer surface of all bones, 80% of all bone makes up the wrists and fingers and toes.
2) trabecular bone; spongy bone, 20% of all bones. ends of the long bones in arms and legs. Faster turn over.

Question 2

What type of bone tends to regenerate faster?

Answer 2

trabecular bones.

Question 3

What’s the main component of the protein matrix? How does the protein matrix of bones harden?

Answer 3

main component of protein matrix is collagen. hardened by minerals- aid in bone strength

Question 4

protein and vitamin C is needed to maintain ____
calcium and minerals is needed to ensure _____ and solidarity
Vitamin D is needed to maintain ____(mineral) supply

Answer 4

protein and vitamin C is needed to maintain collagen
calcium and minerals is needed to ensure strength and solidarity
Vitamin D is needed to maintain calcium and phosphorus(mineral) supply

Question 5

T/F lifting heavy weights and strength training can make the bones more brittle

Answer 5

false. strength training makes bones stronger

Question 6

T/F: bone cells are relatively stable with a long lifespan

Answer 6

false. bonds are constantly being broken down and reformed

Question 7

WHat is an osteoclast? When are they activated?

Answer 7

an osteoclast breaks down bone. Activated when blood calcium gets too low. The osteoclast then breaks down the bone to release more calcium into the blood stream.

Question 8

What is an osteoblast? when are they activated? where are they located? What do they turn into?

Answer 8

osteoblasts re-form bone. When calcium levels in the blood are adequate, osteoclasts stop breaking down bone and the osteoblasts promote bone density and bone growth. Osteoblasts are incorporated into the bone matrix to mature into OSTEOCYTES, which further promote density.

Question 9

When one reaches peak bone mass, bone formation (>//

Answer 9

bone formation>bone breakdown
active osteoblasts>osteoclasts.

Peak bone mass is usually reached during young adulthood, and is when maximum bone density is attained.

Question 10

T/F in women, bone loss is accelerated after menopause.

Answer 10

True. due to decreased estrogen levels

Question 11

What type of technology can determine mineral content and bone mineral density?

Answer 11

Dual XRAY absorptiometry

Question 12

What type of bone does Bone mineral density (BMD) affect most?

Answer 12

trabecular bone is affected more because it has a higher turn over rate and is more susceptible to bone loss.

Question 13

_____ is a disorder characterized by decreased BMD, increased bone fragility, active osteoclasts>osteoblasts, and increased risk of fracture.

Answer 13

osteoporosis

Question 14

T/F If a person is calcium deficient, they should consume phytates and tannins

Answer 14

false. tannins and oxalates reduce calcium absorption

Question 15

T/F if a person is calcium deficient, they should watch their sodium intake

Answer 15

true. if you have too much sodium, your kidneys will filter it out through the urine, causing calcium loss too.

Question 16

Besides bone health, name three other functions that use calcium

Answer 16

1) nerve transmissions
2) muscle contractions
3) blood pressure regulation
4) hormones

Question 17

Name the mechanism of what happens when there are decreased levels of blood calcium

Answer 17

decreased blood calcium —> PTH secretion –> stimulate intestinal Ca2+ absorption, kidney reabsorption, and bone reabsorption (via osteclasts breaking bone down) —> increased blood calcium

Question 18

What is PTH

Answer 18

parathyroid hormone : helps increase blood calcium by telling organs to start absorbing more.

Question 19

What is Calcitonin?

Answer 19

helps to decrease blood calcium by deactivating bone break down and facilitating more calcium excretion

Question 20

Name the mechanism of what happens when there is too much calcium in the blood

Answer 20

increased blood calcium –> calcitonin secretion —> inhibits bone reabsorption –> decreased blood vitamin.

Question 21

What is calcium rigor?

Answer 21

an affect of calcium toxicity that causes the inability for muscles to relax. Calcium toxicity can also lead to kidney stones and impair absorption

Question 22

Cholecalciferol vs calcitriol?

Answer 22

cholecalciferol is a provitamin and a precursor made from dehydrocholesterol in the skin and sunlight. cholecalciferol forms calcitriol, which si the active form of vitamin D.

Question 23

Cholecalciferol vs ergocalicerol

Answer 23

cholecalciferol: vitamin D3 precursor
ergocalicerol: vitamin D2 precursor

Question 24

T/F Vitamin D levels in the body are affected by skin color

Answer 24

true. individuals with darker skin or who wear darker clothes that cover the whole body are at risk for vitamin D deficiencies.

Question 25

The RD of vitamin D is based on the assumption ____

Answer 25

that no vitamin D is made by the skin

Question 26

what’re the two main functions of vitamin D in the body?

Answer 26

1) regulates blood calcium levels (when blood calcium is low/high, vitamin D and PTH/Calcitonin hormones work together to facilitate proper calcium levels via reabsorption or excretion
2) involved in gene expression

Question 27

What is rickets and what is it caused by?

Answer 27

rickets is bone malformation in children caused by improper bone mineralization due to Vitamin D deficiencies

Question 28

T/F people with kidney failure are at risk for a vitamin D deficiency

Answer 28

true, although they can be exposed to sun like anyone else, they lack the mechanism to activate vitamin D.

Question 29

Why does lactose intolerance promote a vitamin D deficiency?

Answer 29

milk is fortified with vitamin D.