25 - Nutrition and MSK Growth

Question 1

What is the most important indicator for nutrition adequecy? How is this measured?

Answer 1

Growth: peak growth and requirements of nutrition per kilogram are during infancy phase.

Growth charts are the best way to measure growth and therefore assess nutrition.

Question 2

At age 0-24 months, what is concern for future nutritional deficiencies or obesity?

Answer 2

<2nd percentile

>98th percentile

Question 3

At age 2-20 years, what is the concern for future nutritional deficiencies or obesity?

Answer 3

<5th percentile: nutritional deficiencies or underweight

>95th percentile: overnutrition or obesity

Question 4

When is it recommended that babies start eating solid foods?

Answer 4

4-6 months of age

Question 5

What aer classic radiograph findings of rickets (VitD deficiency)?

Answer 5

Wide growth plate, flaring at the metaphysis, and cupping at the joints.

Question 6

What is the primary function of VitD?

Answer 6

Maintain calcium and phosphorus levels: promotes absorption of Ca2+ and phosphorus in the GI tract to:

• Support NMJ function
• Support bone calcification

Question 7

What does inadequate VitD cause?

Answer 7

• Decreased calcium absorption
• Prevent Osteoblast action
• Results in failure of the bonse to mineralize = Ricketts

Question 8

Describe the vitD metabolism upon oral intake?

Answer 8

Absorption requires normal fat metabolism, including pancreatic secretions, bile acid, adequate small intestine length, and functioning lymphatic system.

Stored in the liver and activated in the kidney.

Question 9

Describe vitD internal synthesis?

Answer 9

Can be made from UV light by converting cholesterol form to a pre-vitamin D3.

High sun exposure does not guaruntee adequate vitD.

Question 10

What type of people are at risk for a vitamin D deficiency?

Answer 10

1. Inadequate intake: picky eaters, solidly breastfed infants, vegan diets
2. Malabsorption: it’s fat souble and requires pancreatic enzymes for digestions.
3. Dark skin: high melanin protects against UV rays which prevents VitD activation
4. Inadequate sun exposure: common in infants and young children

Question 11

What are the VitD requirements during pregnancy, infancy, and early childhood to adolescence?

Answer 11

Pregnancy: 600 IU

Infancy (0-1yr): 400 IU - concentration is very low in breastmilk. This is the amoutn necessary to prevent rickets.

Early childhood to adolescence (1-18yrs): 600 IU - adequate intake necessary for calcium utilization.

Question 12

What are the most common dietary sources of vitD?

Answer 12

Animal forms: fatty fish (tuna, salmon, trout, mackerel) and dairy products.

Sun exposure (difficult in northern latitudes)

Question 13

What is the function of calcium?

Answer 13

Primary function is to maintain bone structure.

• Also aids in coagulation, endocrine and exocrine function, NMJ activity, and electrophysiology of the heart and smooth muscle.
• Calcium absorption is highly dependent on VitD

Question 14

Who is at risk for calcium deficiency?

Answer 14

1. Preterm infants - majority Ca2+ absorbed in 3rd trimester
2. Glucocorticoid therapy - impairs bone mineralization, decreases absorption, increases renal secretion
3. Inadequate intake
4. Malabsorption
5. Advanged age: less calacium absorbed

Question 15

What are the ways in which malabsorption puts people at risk for a calcium deficiency?

Answer 15

Fat malabsorption leads to calcium deficiency secondary to vitD deficiency (VitD is a fat soluble vitamin)

Question 16

What effect does albumin have on calcium levels? How do you calculate a “corrected calcium”?

Answer 16

Low albumin may cause serum calcium levels to appear low; Albumin has lessed impact on ionized calcium.

Corrected calcium can be used to estimate actual serum calcium in non-critically ill pts: (0.8 x (4-pts albumin)) + serum Ca level

Question 17

What are the calcium requirements during pregnancy/lactation, infancy, and early childhood to adolescence?

Answer 17

Pregnany and lactation: 1300 mg/day

Infancy:

• 0-6mo: 210 mg/day
• 6-12mo: 270mg/day

Early childhood to adolescence:

• 1-3: 500 mg/day
• 4-8: 800 mg/day
• 9-18: 1300 mg/day

Question 18

What are the best dietary sources of calcium?

Answer 18

Dairy (highest bioavailability), broccoli, legumes, and oysters.

Be sure to consume adequate VitD.

Question 19

What is the functon of folic acid?

Answer 19

Coenzyme in the metabolism of nucleic and amino acids by converting homocysteine to methionin (B12 is an essential part of this conversion).

Question 20

What results from a folic acid deficiency during pregnancy?

Answer 20

Congenital abnormalities due to altered metabolism

Closure of neural tube occurs 19-28 days after conception and over have of neural tube defects (NTDs) are suspected to be secondary to folate deficiency.

Question 21

What does folic acid deficiency in adults cause?

Answer 21

Macrocytic anemia.

Question 22

Who is at risk for a folic acid deficiency? What are the recommended doses during pregnancy/lactation and infanct to adolescence?

Answer 22

• People with a low intake of fruits and vegetables.
• Malnourished individuals
• Under-supplemented during pregnancy

Pregnancy/lactation: 500-600microg/day (women with previous NTD require as much as 4000 microg/day

Infancy-adolescence: deficiencey is RARE

Question 23

What are some dietary sources of folic acid?

Answer 23

Fortified grains, dark green vegetables, beans, legumes.

Fortification of grains with folic acid in the late 90s has lead to a decrease in neural tube defects.

Question 24

What nutritional risks may cause someone to be calcium deficient?

Answer 24

• Decreased calcium and VitD intake
• Decreased calcium absorption due to high fiber intake and low VitD intake
• Lactose intolerance

Pre-adolescence provides the “perfect storm” for nutritional deficiency

Question 25

What are some possible intervations if someone is calcium deficient?

Answer 25

Encourage dietary sources:

• supplement non-lactose dairy produts or lactase enzyme containing foods
• leafy greens
• OJ

May require additional supplementation of both Ca and VitD if serum levels are significantly inadequate.

Question 26

When is peak bone mineralization? Why is this important?

Answer 26

Ages 18-20 years old; this is why it’s critical to get an adequate amount of Ca2+ during childhood and adolescent years.