Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
14 Cards in this Set
- Front
- Back
|
When is peak bone density reached; when does it begin to decline? How does it vary by gender?
|
Peak reached before 30, declines at 40 25% boys and 10% girls ages 9-17 reach optimum
|
|
|
Functions of calcium
|
Form and maintain bones and teeth, assists with acid-base balance, transmits nerve impulses, assist in muscle contractions
|
|
|
Low level:
|
parathyroid glands release parathyroid hormone which stimulates activation of vit D
|
|
|
High level:
|
thyroid gland releases calcitonin which inhibits activation of vit D
|
|
|
What are calcium sources, bioavailability considerations
|
Sources: skim milk, low fat cheese nonfat yogurt, green leafy vegs
|
|
|
What nutrient is needed for calcium absorption?
|
Vit D
|
|
|
What factors in food influence absorption?
|
Iron, vit D and binders
|
|
|
If you consume too much calcium, what normally happens?
|
Excess calcium is excreted from the body; hypocalcaemia
|
|
|
High calcium supplementation, however, can result in what?
|
supplements lead to mineral imbalance
|
|
|
If you don’t consume enough calcium, what happens in the long-term?
|
Bone density loss
|
|
|
Vit D sources
|
Fatty fish, egg yolks, fortified milk and cereal
|
|
|
What are the factors affecting synthesis and how long must sun exposure be?
|
Aging: declines to ~25% at age 70, latitudes; 20 to 30 minutes two to three times per week
|
|
|
What if you don’t get enough (children, adults)?
|
Rickets in children and osteomalacia in adults
|
|
|
Know the factors and issues that influence the development (age, gender, genetics, physical activity, lifestyle)
|
Older adults are less able to absorb vit D and participate in less physical activities, women have lower bone density than men, regular exercise causes stress to bones, stimulates increased bone mass, high Na intake causes Ca excretion
|
