Nutrition And Bone Health

Question 1

Serum calcium levels are increased by what

Answer 1

Decreased calcitonin and increase PTH

Question 2

What vitamin deficiency causes osteomalacia/ rickets

Answer 2

Vitamin D deficiency caused by

Decrease dietary intake

Decreased exposure to sunlight

Impaired absorption by intestines and kidneys

Question 3

what is the effect on calcium levels during pregnancy

Answer 3

Calcium absorption is doubled during pregnancy

Increased estrogen levels cause increased osteoblast activity and bone resorption

Skeletal calcium is the predominant source of calcium in breast milk.

Question 4

Female athlete triad

Answer 4

Amenorrhea

Osteoporosis

Disordered eating

Causes impaired bone mass

Question 5

Carbonated soft drinks are associated with what?

Answer 5

Lower bone density

Question 6

Peak bone mass is a product of what

Answer 6

genetics and lifestyle factors

Primarily genetics though.

Question 7

PTH

Answer 7

Increases osteoclast activity

Increases vitamin D activation and decreases Ca excretion via urine.

Question 8

Estrogen and testosterone increase osteoclast or osteoblast activity?

Answer 8

Osteoblast

Question 9

Lactation causes what the bone mass?

Answer 9

Decreases bone mass since the majority of calcium in breast milk comes from skeletal calcium

Question 10

Increase in total body fat causes what to bone mass?

Answer 10

Decreases it.

Total body fat has an inverse relationship to bone density/mass

Question 11

What lifestyle factors have strong evidence supporting a direct effect on peak bone mass

Answer 11

Calcium intake

Vitamin D intake

Dairy intake

DMPA shots (negative effect on bone mass)

Physical activity and exercise

Question 12

Rule of 300 for calcium

Answer 12

Quick rough way to determine the estimated calcium intake someone is having

estimated # of servings of dairy a day x300

add another 300 if its a well balanced diet

Ex: 4 servings of dairy in a well balanced diet = approx. 1500 mg/day of calcium

Question 13

How much dietary Ca2+ is absorbed?

Answer 13

Less than 50%

Question 14

49% of kidney reabsorption of calcium is controlled by what?

Answer 14

PTH

99% of filtered blood calcium is reabsorbed by kidneys

Question 15

What types of vegetables contain very little bio-available Calcium?

Answer 15

High oxalate vegetables

Oxalate is known to impair calcium absorption.

Question 16

What two nutrients directly affect calcium requirements?

Answer 16

Sodium and protein

When sodium and protein concentrations are low, so is calcium intake requirement

however low protein can stimulate PTH hormone due to decreased instance calcium absorption, which would result in bone loss

Question 17

Vitamin D effect on calcium

Answer 17

Essential for intestinal absorption of calcium

Helps also maintain serum calcium and phosphate levels.

Enables normal bone mineralization and prevents hypocalcemia tetany.

Question 18

RDA for vitamin D with respect to age groups

Answer 18

0-12 months = 400 IU

1-70 yrs = 600 IU

71+ = 800 IU

Question 19

Groups @ risk for Vit. D deficiency

Answer 19

Breastfed infants

Older adults

Limited sun exposure

Inflammatory bowel diseases

Obese populations or people who have undergone bypass surgery.

Question 20

Vitamin A deficiency and excess affect on bone

Answer 20

• only affects through supplements*

Deficiency can lead to osteomalacia type symptoms

Excess can lead to hypercalcemia

Question 21

Magnesium affects on bone

Answer 21

Involved directly with osteoblast and clast balancing

Deficiency leads to osteoporosis and bone stiffness due to over abundance of hydroxyapatite crystals.

Deficiency also hyper-stimulates osteoclasts and blasts

Should never take magnesium and calcium supplements together. Has shown to decrease calcium absorption

Question 22

Vitamin K effects on bone

Answer 22

Involved in carboxylation of osteocalcin.

Ultimately inhibits osteoclastgenesis and promotes osteoblast genesis

Deficiencies cause increased fracture risk and osteoporosis.

Question 23

Vitamin C effects on bones

Answer 23

Cofactor for hydroxylation of lysine and proline during collagen synthesis

Helps generate cartilage, which some is used for Endochondral ossification of bone.

Daily recommendations = 400mg

Question 24

Fluoride effect on bone

Answer 24

Unknown however is hypothesized to stimulate osteoblasts but can contribute to bone fragility if too high.

Supplementation is not approved

Question 25

Caffeine affect with bone

Answer 25

Small effect on decreased calcium absorption

Overall not really an effect