NUSC 1165: Chapter 8 Latest Exam
Questions With Solved Solutions
Graded A+.
What are vitamins? - Answer •Organic compounds required from the diet in small amounts.
•Vitamins are necessary to promote and regulate the chemical reactions needed for growth,
reproduction, and maintaining health.
•Deficiency occurs when a vitamin is lacking in the diet.
•Vitamin classification is based on solubility properties.
Vitamin Classification - Answer Water soluble: vitamin C, vitamin B (thiamin, riboflavin, niacin,
biotin, pantothenic acid, vitamin B6, folate, vitamin B12
Fat soluble: vitamin A, vitamin D, vitamin E, vitamin K
Fortified and Enriched Foods - Answer ¢Fortification
Process of adding nutrients to foods.
The added nutrients are generally not found in the food, such as fortifying orange juice with
calcium.
Government-Mandated Fortification Programs
¢Purpose is to increase nutrient intake in populations, reduce deficiencies.
Cautious with potential nutrient toxicity
¢Enrichment
Adding nutrients back to foods that have lost nutrients due to processing.
An example is the addition of B vitamins to white rice.
Dietary Supplements - Answer ¢Dietary supplements are another source of vitamins in the
modern diet.
, ¢Dietary supplement production is not supervised by the FDA.
Bioavailability of Vitamins - Answer ¢Bioavailability refers to the amount of a nutrient that can
be absorbed and utilized in the body
Approximately 40-90% of vitamins are absorbed in the small intestine.
Fat-soluble vitamins require fat in the diet to be absorbed.
Water-soluble vitamins may require transport molecules or specific molecules in the GI tract.
¢Factors affecting bioavailability of vitamins
Solubility
Energy-requiring transport system
Carrier proteins
¢Some vitamins are absorbed in inactive provitamin or vitamin precursor forms that must be
converted into active forms by the body.
Absorption of Vitamins - Answer Steps to Vitamin Absorption:
•Mouth: The vitamins are released from the food due to chewing, or mechanical digestion.
•Stomach: This is where protein digestion takes place, and some vitamins are released from the
food matrix in this organ.
•For a brief review for the final, we learned in Chapters 3 and 6 that hydrochloric acid is
released from the stomach cells to activate the protein-digesting enzyme pepsin.
•Gallbladder: This organ stores and releases bile for fat digestion. The bile helps to absorb fat-
soluble vitamins.
•Pancreas: This organ produces and releases digestive enzymes (amylase, lipase, trypsin,
chymotrypsin) that aid in releasing vitamins directly from food.
•Small Intestine: Note the key differences between the fat-soluble vitamins and fat-soluble
vitamins in this organ.
•Fat Soluble Vitamins: Fat-soluble vitamins are digested with fats (also known as lipids) and
therefore incorporated with the fats and bile to form the micelle.
•The fat droplets from the micelles diffuse through the brush border membrane via simple
diffusion. In Chapter 3, we learned about simple diffusion where the concentration gradient is
from high to low outside to inside of the mucosal cell. No energy or carrier protein is required.
Questions With Solved Solutions
Graded A+.
What are vitamins? - Answer •Organic compounds required from the diet in small amounts.
•Vitamins are necessary to promote and regulate the chemical reactions needed for growth,
reproduction, and maintaining health.
•Deficiency occurs when a vitamin is lacking in the diet.
•Vitamin classification is based on solubility properties.
Vitamin Classification - Answer Water soluble: vitamin C, vitamin B (thiamin, riboflavin, niacin,
biotin, pantothenic acid, vitamin B6, folate, vitamin B12
Fat soluble: vitamin A, vitamin D, vitamin E, vitamin K
Fortified and Enriched Foods - Answer ¢Fortification
Process of adding nutrients to foods.
The added nutrients are generally not found in the food, such as fortifying orange juice with
calcium.
Government-Mandated Fortification Programs
¢Purpose is to increase nutrient intake in populations, reduce deficiencies.
Cautious with potential nutrient toxicity
¢Enrichment
Adding nutrients back to foods that have lost nutrients due to processing.
An example is the addition of B vitamins to white rice.
Dietary Supplements - Answer ¢Dietary supplements are another source of vitamins in the
modern diet.
, ¢Dietary supplement production is not supervised by the FDA.
Bioavailability of Vitamins - Answer ¢Bioavailability refers to the amount of a nutrient that can
be absorbed and utilized in the body
Approximately 40-90% of vitamins are absorbed in the small intestine.
Fat-soluble vitamins require fat in the diet to be absorbed.
Water-soluble vitamins may require transport molecules or specific molecules in the GI tract.
¢Factors affecting bioavailability of vitamins
Solubility
Energy-requiring transport system
Carrier proteins
¢Some vitamins are absorbed in inactive provitamin or vitamin precursor forms that must be
converted into active forms by the body.
Absorption of Vitamins - Answer Steps to Vitamin Absorption:
•Mouth: The vitamins are released from the food due to chewing, or mechanical digestion.
•Stomach: This is where protein digestion takes place, and some vitamins are released from the
food matrix in this organ.
•For a brief review for the final, we learned in Chapters 3 and 6 that hydrochloric acid is
released from the stomach cells to activate the protein-digesting enzyme pepsin.
•Gallbladder: This organ stores and releases bile for fat digestion. The bile helps to absorb fat-
soluble vitamins.
•Pancreas: This organ produces and releases digestive enzymes (amylase, lipase, trypsin,
chymotrypsin) that aid in releasing vitamins directly from food.
•Small Intestine: Note the key differences between the fat-soluble vitamins and fat-soluble
vitamins in this organ.
•Fat Soluble Vitamins: Fat-soluble vitamins are digested with fats (also known as lipids) and
therefore incorporated with the fats and bile to form the micelle.
•The fat droplets from the micelles diffuse through the brush border membrane via simple
diffusion. In Chapter 3, we learned about simple diffusion where the concentration gradient is
from high to low outside to inside of the mucosal cell. No energy or carrier protein is required.
