M1.2 — 1 bone growth and development Flashcards
(32 cards)
approximately __-__% of adult bone is accrued during the adolescent years
40-60
in young kids, bone turnover (osteoblasts/osteoclasts) is __% per year
50%
bone turnover is regulated by nutrition and what 5 others things?
cytokines
parathyroid hormone
vit D3
insulin-like growth factor 1 (IGF-1)
calcitonin
how many bones are in the adult human body? how many in the neonate?
206
275
__% of the bodies calcium is found in the skeleton
99%
we absorb only about __% of calcium from foods
30%
MicroCrystalline HydrocyApatite (MCHA) is the actual form of _____ found in bones. As a supplement it stimulates _____ and is well absorbed. Which form is poorly absorbed?
calcium
osteoblasts
calcium carbonate is poorly absorbed
what is the RDA for calcium in 1-3yo, 4-8 yo, 9-18yo?
1-3 yo: 700-2500 mg/day
4-8 yo: 1000-2500 mg/day
9-18 yo: 1300-3000 mg/day
what are food sources of calcium?
- milk/dairy (counts for about 75% of intake)
- green leafies
- broccoli
- intact salmon and canned sardines
- nuts, seeds, beans and shellfish (small amounts only)
AKA calciferol
vitamin D3
a fat soluble hormone necessary for calcium absorption and utilization
vitamin D3
Why are children and adolescents who are obese at increased risk for Vit D3 deficiency?
possibly because of sequestration of Vit D in body fat
Vit D3 is synthesized in the skin from 7-dehydrocholesterol on exposure to sunlight, binds to Vit D binding protein and is transported to the ___ where is undergoes hydroxylation to form 25-hydroxyvitamin D (25-OH-D). The half life is 2-3 weeks
liver
to get proper Vit D3 levels, you need __ minutes of arm and leg exposure - x/week
15 minutes, 3-5x/week (more if darker skinned)
sunscreen of what power blocks UV and synthesis of Vit D3?
8+
what are the upper limits RDA of Vit D3 at 0-6months? 6-12 months? 1-3yo? 4-8yo? 9-18yo? adults?
0-6months = 1000 IU/day
6-12 months = 1500
1-3yo = 2500
4-8yo = 3000
9-18yo = 4000
adults = 5-8000
what are food sources of Vit D3?
- cod liver oil
- fatty fish (wild caught salmon, tuna, sardines)
- hard boiled eggs
- mushrooms
- fortified milk and cereals
- sour cream, yogurt, butter
kids taking anti-fungal, anti-convulsense, glcocorticoids, anti-retroviral medications should be taking _-_x the recommended amount of Vit D3
2-3x
Vitamin K2 is fat soluble, but breaks down quickly and excreted. It supports bone ________ and may have a synergistic role with Vitamin __
mineralization
Vit D3
sources of Vit K2?
- produced by gut bacteria
- green leafies (spinach, kale, broccoli, brussels sprouts)
- grass-fed meats and dairy
__% of magnesium is found in the skeleton. It stimulates ___
60%
osteoblasts
fluoride/fluorine stimulates ______ and inhibits ______
It is are incorporated into ____
stimulates osteoblasts, inhibits osteoclasts
appetite crystals
Omega 3’s reduce inflammation which interferes with ______, therefore, consumption can enhance production of new bone
osteoblasts
Omega 3’s help ____ bind to the bone cell membrane
estrogen
