Topic D: Nutrition and Supporting Sciences Flashcards
Vitamins Needed for Energy Production
Thiamin (B1), Riboflavin (B2), Niacin (B3), and Pantothenic Acid (B5)
Thyroxine
Regulates metabolism and rate of oxidation
- Makes glucose available by stimulating liver glycogenolysis (breakdown of glycogen –> glucose) and gluconeogenesis (conversion of non-carbs –> carbs)
BMR is highest when?
Ages 0-2
Indirect Calorimetry
Measures O2 consumption and CO2 excretion using a portable machine
- A practical way of measuring which nutrients are being used for energy & determining calorie needs
How to lower RQ
Increase fat intake
Sweetest sugar
Fructose
How does sorbitol (an alcohol from glucose) compare to glucose in terms of sweetness?
Sorbitol is slightly less sweet
3 Amino Acids that contain Sulfer
Cysteine, cystine, and methionine
Soybeans are low in what amino acid?
Methionine
Most polyunsaturated fat
Safflower oil
Most unsaturated fat
Canola oil
Most saturated fat
Coconut oil
Most monounsaturated fat
Olive oil
Linoleic Acid is what type of fat?
Omega-6
A lack of linoleic acid can lead to…
Poor growth rate (and eczema, petechiae)
If linoleic acid replaces CHO
LDL decreases, HDL increases
If linoleic acid replaces saturated fat
Total cholesterol and HDL decrease
Alpha-linolenic acid is what type of fat?
Omega-3
Effect of alpha-linolenic acid consumption
- Decreased hepatic production of TAG (inhibits VLDL synthesis)
- Little effect on total cholesterol levels
Examples of alpha-linolenic acid
EPA and DHA
In fats, how is the omega sign designated?
By the location of he first double bond, counted from the METHYL END of the fatty acid
Best sources of trans fat
Margarines, shortenings, frying fats
Why does fat provide more energy than CHOs?
Fat has more carbon atoms for oxidation
Winterized Oil
Won’t crystalize when cold; useful in prepping salad dressings
Functions of Vitamin A
Skin, vision
Sources of Vitamin A
Yellow & orange fruits, dark leafy green veggies
Cantaloupe, carrots, sweet potato, apricots, fish, liver, fortified skin milk
Earliest sign of Vitamin A Deficiency
Nyctalopia (night blindness)
One of the least toxic vitamins
Vitamin E
Functions of Vitamin E
- *Antioxidant
- Resists hemolysis of RBC
Sources of Vitamin K
Green, leafy veggies (spinach, kale, broccoli)
Stability of Thiamin when cooking
- Heat stable in acid
- Lost as temp or pH rises (during cooking)
Function of Thiamin (B1)
CHO Oxidation (B1 needs increase when CHO intake increases)
Signs of Thiamin Deficiency
Beriberi, muscle weakness, foot drop, memory loss, tachycardia
- Decreased erythrocyte transketolase
- Increased plasma pyruvate (a clinical indicator)
Signs of Riboflavin Deficiency
- *Cheilosis (cracked lips)
- *Magenta tongue
- Angular stomatitis (mouth corner cracks, sore throat)
- Growth failure
As the body’s energy expenditure increases, the need for what also increases?
- Thiamin (B1)
- Riboflavin (B2)
- Niacin (B3)
- Pantothenic Acid (B5)
Sources of folate
- Fortified dry cereal
- Liver
- Kidney
- Green leafy veggies
- Citrus fruits
- Lentils
- Beans
As protein intake increases, what vitamin is needed in larger amounts?
Pyridoxine (B6)
Function of Pantothenic Acid
Acts as Coenzyme A in energy release
How is biotin synthesized?
By intestinal bacteria
Most abundant mineral in the body
Calcium
Calcium is regulated by
Parathyroid hormone
Calcium absorption is aided by…
- Vitamin D
- Acid
- Lactose
Effect of calcitonin on serum calcium
Calcitonin lowers serum Ca by inhibiting bone resorption
Sign of Vitamin C deficiency
Bleeding gums
Sources of Phosphorus
Animal proteins
- Meat
- Poultry
- Fish
- Milk
- Eggs
- Cheese
Type of iron that absorbable
Ferrous
Sources of iron
Heme: Animal foods (meat, fish, poultry)
Non-Heme: Cereals, veggies
Form of iron that’s poorly absorbed
Non-heme
How to increase iron absorption
- Gastric juice
- Vitamin C
Influence of Calcium on Iron Absorption
Calcium helps if oxalates are present
- Oxalates in diet bind to iron. If Ca is also in the diet, Ca will bind to the oxalates first, which frees up iron for absorption
What increases Mg needs?
High intakes of protein, calcium, or vitamin D
Decreased serum copper is associated with what?
Wilson’s Disease
Sources of Sulfur
Animal proteins
- Meat
- Poultry
- Fish
- Eggs
Insensible water loss (skin, breathing) per day
0.8-1.2 L/day
Atomic Weights & Valence of Sodium
AW: 23
Valence: 1
Atomic Weights & Valence of Potassium
AW: 39
Valence: 1
Atomic Weights & Valence of Calcium
AW: 40
Valence: 2
Normal range of sodium
136-145 mEq/L
Symptoms of Dehydration
- Nausea
- Dizziness
- Sunken eyes
- Fever
- Hyperventilation
- Excessive sweating
- Headache
- Fatigue
- Decreased appetite
- Rapid weight loss
Acid/Base Balance: Lungs control…
Carbonic Acid (An acid, H2CO3)
Acid/Base Balance: Kidneys control
Bicarbonate (A base, HCO3)
Weight gain guidelines during pregnancy: Normal weight female (BMI 18.5-24.9)
25-35 lbs
Weight gain guidelines during pregnancy: Underweight female (BMI < 18.5)
28-40 lbs
Weight gain guidelines during pregnancy: Overweight female (BMI 25-29.9)
15-25 lbs
Weight gain guidelines during pregnancy: Obese female (BMI >/= 30)
11-20 lbs
High-risk pregnancies:
- Who is at highest risk?
- Weight gain goals
- Black and very young (teenage) women
- Weight gain goals: Strive for upper end of weight gain ranges to reduce risk
Weight gain goals during pregnancy
First 3 months: 1 lb/month
Months 4-9: 1 lb/week
Pregnancies defined as “at-risk”
- Failure to gain 4 lbs/month in last half of pregnancy
- < 16 or 35+ years old
- < 12 months between pregnancies
Pregnant adolescents have increased needs of what?
Iron, calcium, zinc
Role of linolenic acid in pregnancy
Development of the fetal nervous system
Normal birth weight
2500-4000 g
Low birth weight (LBL)
< 5.5 lbs (2500 g)
Very low birth weight (VLBW)
< 3.3 lbs (1500 g)
Extremely low birth weight (ELBW)
< 1000 g
Small for gestational age (SGA)
< 10th percentile birth weight for gestational age
Appropriate for gestational age (AGA)
10th to 90th percentile
Large for gestational age (LGA)
> 90th percentile
Estimated Energy Requirement for Babies 0-6 months
Female: 520
Male: 570
Estimated Energy Requirement for Babies 7-12 months
Female: 676
Male: 743
Breastfeeding Recommendations
Exclusively breast-feed for first 6 months, then supplement by weaning foods for at least up to 12 months
2 Supplements needed by breastfed infants
Per day: 400 IU Vitamin D and 0.25 mg fluoride
Infant formula needs
2.5 oz/lb/day
When should solid foods be introduced to babies?
4-6 months; when sitting posture can be sustained and extrusion reflex diminishes
(begin with iron-fortified cereal, then strained veggies or fruit)
Weight for length/stature
- Normal range
- Reflects…
Normal Range: 5th-95th percentile
Reflects short-term changes in nutritional status
Stature/length for age
- Normal range
- Reflects…
Normal Range: >/= 5th percentile
Reflects long-term nutritional status (determines the extent of stunting)
Weight for age
- Normal range
- Reflects…
Normal range: 5th-95th percentile
A short-term marker of growth; affected by acute nutritional stress or illness
BMI for age percentiles
Underweight: < 5th
Healthy weight: 5-84th
Overweight: 85th to 94th
Obese: >/= 95th or BMI > 30
Failure to thrive may result from:
- Lack of fiber leading to chronic constipation
- *Diminished intake
- Acute or chronic illness
- Restricted diet
- Poor appetite
RDAs for Protein (19+ years old)
Male: 56 g
Females: 46 g
During and after endurance physical activity, consume what 3 things?
Fluid, CHOs, Sodium
Primary energy source at rest and during normal activities
Fat
During prolonged exercise, how does energy utilization change?
Increased reliance on CHO to provide pyruvate for continued lipid oxidation
Botanicals that may interact with anticoagulants
- Black cohosh
- Garlic
- Ginger
- Ginkgo biloba
- Ginseng
The liver produces what?
Bile
The liver stores what?
Glycogen
The liver synthesizes what?
Glucose
Where does protein digestion begin?
The stomach
How are the enzymes of the small intestine and pancreas able to operate at a more neutral pH?
Fluids are secreted (ex - bicarbonate in the pancreas) that help neutralize the acidic chyme
What does the large intestine absorb?
Water, salts, and the vitamins synthesized by bacteria
Bacteria convert fibers into?
Short-chained fatty acids (acetate, butyrate, propionate, lactate)
Function of SCFAs
- Stimulate water and sodium absorption in the colon
- Provide substrates for energy production
Where does lactase come from?
The small intestine
Enzymes for CHO digestion are available in what order?
- Maltase, sucrase (~week 30 of gestation)
- Lactase (reaches adult levels @ birth)
- Pancreatic amylase (remains low for 6 months after birth)
Glucogenic Amino Acids
- What are they?
- What % of AA are glucogenic?
- AA that yield glucose following deamination
- 58% of AA are glucogenic
Most glucogenic amino acid
Alanine (the alanine-glucose cycle)
Hormones that decrease blood glucose
Insulin
Hormones that increase blood glucose
- Glucagon
- Glucocorticoids
- Epinephrine
- Growth Hormone (ACTH)
What happens to blood glucose levels during catabolic stress?
Epinephrine suppresses insulin secretion, which elevates blood glucose levels
Effect of glucocorticoids on blood glucose? How?
Increase blood glucose by catabolizing protein –>glucose (gluconeogenesis; requires pyridoxine)
End products of glucose metabolism
Energy (ATP), CO2, and water
Purpose of glycolysis
To produce pyruvate for the Kreb’s Cycle by breaking down glucose (with or without oxygen) into pyruvate or lactate
End product of aerobic glycolysis
Pyruvate
End product of anaerobic glycolysis
Lactate
What occurs in the cori cycle?
Lactate is released from tissues, transported to liver, and converted back to pyruvate
What are required to convert pyruvic acid –> acetyl CoA?
Thiamin (B1), Riboflavin (B2), Niacin (B3), Pantothenic Acid (B5), Magnesium, lipoic acid
Intermediate breakdown product of all 3 macronutrients
Acetyl CoA
How does fat enter the TCA cycle?
A two-carbon fragment
What is required to convert pyruvate –> oxaloacetate?
Biotin
Reversible Reactions in Energy Metabolism
Glucose-6-Phosphate to/from Glycogen
Glucose-6-Phosphate to/from Pyruvic Acid
Pyruvic Acid to/from Lactic acid (Cori cycle)
Irreversible Reactions in Energy Metabolism
Pyruvic Acid –> Acetyl CoA
The transition from glycolysis to the TCA cycle
In protein metabolism, what is needed to transport AA? Where do they travel to/from?
Pyridoxine transports AA from intestinal villi capillaries –> portal bloodstream
3 Branched Chain Amino Acids
Leucine, Isoleucine, Valine
“LIV”
Function of Adrenal Steroids (Glucocorticoids)
Stimulate protein catabolism (stimulate gluconeogenesis, which releases glucose from protein)
How are most nutrients absorbed?
Active transport
Glucose, AA, Na, K, Mg, Ca, Fe
What is required for Vitamin D absorption?
The acidity of the chyme in the stomach
Vitamin B12 absorption:
- Where does it occur?
- Requires what?
- Occurs in the ilium
- Requires stomach secretions (HCl and intrinsic factor)
Effect of Insulin on blood glucose
Decreases blood glucose: Beta cells of pancreas produce insulin, which induces cells to take up blood glucose
Effect of Glucagon on blood glucose
Increases blood glucose: Alpha cells of pancreas produce glucagon, which converts liver glycogen –> glucose (glycogenolysis)
Effect of Glucocorticoids on blood glucose
Increase blood glucose: Convert protein –> glucose (gluconeogenesis); Requires pyridoxine
Effect of Epinephrine on blood glucose
Increase blood glucose:
- Stimulates liver and muscle glycogenolysis (glycogen –> glucose)
- During catabolic stress, it decreases insulin release from the pancreas
Epinephrine:
- Where is it produced?
- Other than its effects on blood glucose, epinephrine stimulates what?
- Produced in the adrenal medulla
- Stimulates the sympathetic nervous system
Effect of Growth Hormone on blood glucose
Increases blood glucose (is an insulin antagonist)
Effect of ACTH (adrenocorticotropic hormone) on blood glucose
Increases blood glucose (is an insulin antagonist)
