Kin 101 Chapter 11
While breastmilk has a near-perfect nutritional profile for infants, breastmilk is low in vitamin D. Formula-fed infants who do not receive much sunlight may also be at risk for vitamin D deficiency. The American Academy of Pediatrics recommends that all children receive how much vitamin D per day?
400 IU
Levels of calcium in the blood are tightly regulated. When blood levels of calcium start to drop below normal, which of the following physiological responses may take place?
Intestines absorb more calcium. Bones release calcium into the blood. The kidneys retain more calcium.
Dairy foods are rich sources of calcium, but many people with lactose intolerance cannot consume these foods without experiencing gastrointestinal discomfort. Fortunately, there are a number of nondairy sources of calcium. Rank the following nondairy foods in order of calcium content.
MOST CALCIUM: LEAST CALCIUM:
From each pair, click to select the factor that increases vitamin D synthesis.
Summer Texas Age 23 Outdoors
True or false: Calcium-fortified orange juice contains vitamin D in amounts comparable to fortified cow's milk.
TRUE
How does obesity (BMI >30) affect vitamin D availability?
The release of vitamin D synthesized from exposure to the sun and stored in subcutaneous fat is less efficient in people with excess body fat.
The American Academy of Pediatrics recommends that all infants and children, starting shortly after birth, have a minimum daily intake of 400 IU of vitamin D. Infants are likely to require supplemental vitamin D because
breast milk is a poor source of vitamin D.
The primary objective of the WHI Hormone Therapy trial was to assess the effects of post-menopausal hormone replacement therapy on risk for ______.
coronary heart disease
The study analyses revealed the strength of relationships between calcium and vitamin D supplementation and a variety of health parameters. In the analyses presented in this research paper, calcium and vitamin D supplementation ______ risk of hip fracture.
decreased
The primary endpoint of the WHI Calcium and Vitamin D supplementation trial was ______.
hip fracture
Analyses showed that women who took calcium and vitamin D supplements had higher risk of
kidney stones.
Vitamin D deficiency during childhood leads to a condition of weak and malformed bones known as ______.
rickets
Vitamin D is unique in that it can be obtained by the diet but also is synthesized inside the body when a cholesterol-like substance is activated by sunlight and converted to the prohormone vitamin D. Which of the following organs participate in vitamin D synthesis as a result of sunlight exposure?
Bone Skin KIdneys Liver
The women enrolled in the WHI clinical trial received
500 mg calcium + 200 IU vitamin D twice per day OR placebo twice per day.
Although approximately 85% of phosphorus in the body is found in the bones, the other 15% that exists in the blood, soft tissues, and extracellular fluids has a wide range of functions. From the list below, check all of the functions of phosphorus.
Activates many enzymes Participates in cellular replication and growth Participates in energy metabolism
In bone, magnesium contributes to bone strength and rigidity, but it also has multiple other roles in the body. Which of the following are roles of magnesium?
After muscle contraction, magnesium participates in muscle relaxation. In contrast to calcium, magnesium functions to increase blood pressure. Magnesium is a cofactor for enzymes in energy metabolism. Magnesium is involved in the synthesis of vitamin D in the liver.
Prior analysis of the WHI-CaD trial showed that supplementation with calcium and vitamin D modestly reduced risk of hip fracture. The analysis presented in this paper added to the original analysis because the researchers analyzed
All of the choices are correct.
Tetany is a condition in which the muscles are unable to relax, leading to stiffness and involuntary twitching. Problems with which of the following functions of calcium could contribute to tetany?
Calcium is required for muscle contraction. Calcium helps to regulate blood pressure. Calcium helps to regulate cellular differentiation. Calcium assists in the release of neurotransmitters during nerve impulse conduction.
Although moderate weight-bearing exercise has a positive effect on the development and maintenance of bone mass, excessive exercise can be detrimental to bone health for women. Which of the following explains why excessive exercise can be detrimental to bone health?
Excessive exercise without sufficient energy intake can accelerate bone loss through insufficient estrogen levels
Participants in the WHI clinical trial were not allowed to take any other dietary supplements besides the treatment or placebo.
FALSE
The low fat content of vitamin D-fortified orange juice limits the bioavailability of vitamin D.
FALSE
As a mother of young children, Laura is concerned about her kids' dental health because they live in a community that does not have fluoridated water. Fluoride helps protect against dental caries. Where else can her kids get fluoride?
Fluoridated toothpaste
Categorize the bone-building nutrients based on their specific roles in maintaining bone health.
Formation of Hydroxyapatite: Calcium Phosph Fluoride Regulates mineral absorption: Vitamin D Formation of collagen matrix: Zinc Vitamin C Copper
How does phosphorus contribute to bone health?
Phosphorus is a component of hydroxyapatite crystals, which lend strength to bones and teeth
Several technologies exist today to help health care professionals determine osteoporosis risk. Check all of the following methods that are used to assess bone health.
Quantitative ultrasound Quantitative computed tomography Dual-energy x-ray absorptiometry
Click to select the foods that are good sources of calcium. (A good source is one that provides at least 10% of the Daily Value for a nutrient.)
Salmon chicken
To prevent fractures, which of the following is a reasonable application of the results of this study?
Strive to meet the RDA for calcium and vitamin D from a combination of foods and dietary supplements.
There are two types of osteoporosis. Classify each statement according to whether it is a characteristic of type 1 or type 2 osteoporosis.
TYPE 1: affects trabecular bone most common between 50 - 60 years directly linked w decreased estrogen TYPE 2: commons diagnosed later in life occurs in both men and woman affects cortical and trabecular bone at same rate
The balance between bone resorption and synthesis changes over the lifespan. Which of the following best describes bone remodeling in a 45-year-old adult?
The activity of osteoclasts exceeds the activity of osteoblasts, leading to a net decrease in bone mass.
Which mineral is most important throughout life to assist in maintaining strong bone?
calcium
Vitamin D regulates the absorption of ______ from the small intestine.
calcium and phosphorus
A variety of factors can influence osteoporosis risk. From each of the following pairs, click to select the factor that increases osteoporosis risk
felmale, slender, smoking cigs,
The WHI-HR trial was stopped early because
interim analyses revealed increased risk for breast cancer and coronary heart disease for women on HRT.
Click to select the foods that are good sources of vitamin D. (A good source is one that provides at least 10% of the Daily Value for a nutrient.)
milk yogurt tofu spinach orange juuuuuuuice
Compared to people with fair skin, individuals with dark skin pigmentation require ______ sun exposure to synthesize adequate vitamin D.
more
You know that vitamin D is fat soluble. Does this mean you need the fat in whole milk to absorb vitamin D? Researchers at Boston University compared the bioavailability of vitamin D from whole milk, skim milk, and fortified orange juice. Look through the research article (see LINK TO ARTICLE). Results of this study showed that bioavailability of vitamin D was
similar for milks of differing fat contents.
Which of the following is not considered a weight-bearing activity?
swimming
For this analysis, women from the WHI observational study were considered calcium users if they
took at least 500 mg calcium per day.
Several of the vitamins or minerals involved in bone health also play important roles in prevention of chronic disease. Match each micronutrient with its role in disease prevention.
Influences cell development; may reduce risk for cancer. :vitamin D Decreases blood pressure; prevents heart rate abnormalities: magnesium Decreases blood pressure; improves blood lipid profile: calcium
Which of these food items provides the greatest amount of phosphorus?
1 cup of trail mix
