Calcium and Bone Health Quiz

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Questions and Answers

What role does calcium play in maintaining normal blood pressure?

It increases blood viscosity.

It activates cellular enzymes that regulate many processes. (correct)

It directly influences heart rate.

It promotes vasodilation of blood vessels.

Which of the following dietary changes may reduce the risk of hypertension?

Increasing sodium intake

Reducing potassium consumption

Following the DASH diet (correct)

Eliminating dairy entirely

What percentage of calcium do adults typically absorb from their diet?

30% (correct)

10-15%

50-60%

20-25%

Which factor is known to enhance calcium absorption?

Vitamin D Signup and view all the answers

What outcomes are associated with low blood calcium levels?

Calcium tetany Signup and view all the answers

What is a potential consequence of inadequate calcium intake during adulthood?

Osteoporosis Signup and view all the answers

What hormones are involved in the regulation of calcium levels in the body?

Calcitonin and parathyroid hormone Signup and view all the answers

Which of the following statements about osteoporosis is correct?

There is usually a lack of noticeable signs until fractures occur. Signup and view all the answers

What is the primary component of the protein matrix in bones?

Collagen Signup and view all the answers

What is the recommended dietary allowance (RDA) of vitamin D for adults aged 19-70 years?

600 IU (15 ug) daily Signup and view all the answers

Which of the following is a primary function of magnesium in the body?

Assists in normal muscular contraction/relaxation Signup and view all the answers

What is the function of osteoclasts in bone health?

Break down bone Signup and view all the answers

Which food source is NOT considered a good source of magnesium?

White bread Signup and view all the answers

What percentile of body calcium is typically stored in bones and teeth?

Approximately 99% Signup and view all the answers

What can be a potential symptom of magnesium deficiency?

Loss of appetite Signup and view all the answers

Which nutrient is not essential for bone mineralization?

Iron Signup and view all the answers

What is the upper limit (UL) of magnesium intake for adults from non-food sources?

350 mg/day Signup and view all the answers

What happens to osteoblast activity as a person ages?

It decreases Signup and view all the answers

Which factor is least likely to affect bone health?

Political views Signup and view all the answers

How does smoking affect bone health?

Reduces bone density Signup and view all the answers

What mineral is known to displace hydroxyapatite in bone, promoting resilience?

Fluoride Signup and view all the answers

What is a potential adverse effect of excess calcium intake from supplements?

Kidney stones Signup and view all the answers

What is the recommended daily allowance (RDA) of calcium for adult women over the age of 51?

1200mg Signup and view all the answers

Which of the following is a function of phosphorus in the body?

Assists in energy transfer Signup and view all the answers

What is the upper limit (UL) of phosphorus intake recommended for adults?

4000mg Signup and view all the answers

Which of the following foods is considered a good source of calcium?

Almonds Signup and view all the answers

How does the body synthesize vitamin D?

By exposure to sunlight Signup and view all the answers

What condition may arise from phosphorus excess in the body?

Kidney calcification Signup and view all the answers

Which factor does NOT affect sun exposure for vitamin D synthesis?

Body weight Signup and view all the answers

What is a common consequence of prolonged Vitamin D deficiency in adults?

Osteoporosis Signup and view all the answers

Which factor can increase the risk of Vitamin D deficiency?

Dark skin Signup and view all the answers

How does Vitamin D affect the immune system?

It stimulates the maturation of immune cells Signup and view all the answers

What is a potential effect of excess Vitamin D intake?

Calcium deposits in organs Signup and view all the answers

Which dietary source is naturally rich in Vitamin D?

Fatty fish Signup and view all the answers

What is the recommended daily intake of Vitamin D for infants and children in Canada?

400 IU Signup and view all the answers

Which of the following is a risk factor for Vitamin D deficiency?

Breastfeeding without supplementation Signup and view all the answers

What health issues can result from Vitamin D deficiency in children?

Rickets Signup and view all the answers

What is a primary function of fluoride in dental health?

It acts to suppress bacteria metabolism in plaque. Signup and view all the answers

Which of the following describes a recommended intake of fluoride for women?

3 mg/day Signup and view all the answers

What condition can result from fluoride excess?

Fluorosis Signup and view all the answers

What role does vitamin K play in bone health?

It helps in the synthesis of proteins needed for bone formation. Signup and view all the answers

Which group is at the highest risk of developing osteoporosis?

Older women Signup and view all the answers

What is one reason for bone loss in males as they age?

Decrease in testosterone levels Signup and view all the answers

What diagnostic method is used to assess bone mineral density?

Dual-energy X-ray absorptiometry (DEXA) scan Signup and view all the answers

Which of the following is considered a non-modifiable risk factor for osteoporosis?

Older age Signup and view all the answers

Which factor can help improve bone density?

Strength-training exercises Signup and view all the answers

How can heavy body weight influence bone health?

It places stress on bones, increasing density. Signup and view all the answers

Study Notes

Nutrients for Bone Health

Bones are made of mineral crystals and protein (collagen).
Mineral crystals provide strength.
Protein provides flexibility.
Two types of bones: cortical and trabecular.
Blood vessels and nerves run through the center of bones.
Bone health is defined by bone mineral density (how tightly mineral crystals are packed into the protein matrix).
Bones are metabolically active, constantly being broken down and rebuilt by osteoclasts and osteoblasts.
Bone growth in length occurs from conception to teenage years, and density may continue to accrue into young adulthood.
Bone lengthening usually stops around age 14 for females and 17 for males.
Bone loss is influenced by genetics, nutrition, and physical activity.

Factors Affecting Bone Health

Genetics
Weight-bearing activity
Alcohol consumption
Animal protein consumption
Smoking
Adequate nutrient intake
Sleep
Body weight

Nutrition for Bone Health

Collagen is supported by protein and Vitamin C.
Mineral crystals are supported by Calcium, Phosphorus, Magnesium, Fluoride, Vitamin D, and Vitamin K.

Calcium in Bones

Calcium is the most abundant mineral in the body.
Approximately 99% of calcium is stored in bones and teeth.
Functions as an integral part of bones, working with phosphorus.
Bones release calcium into body fluids when blood calcium levels decrease.
Bone mineral formation and dissolution are constantly occurring.
Hydroxyapatite is the chief crystal in bone formation.
Fluorapatite, a fluoride compound, resists bone dissolution to maintain bone integrity.
Only ~1% of calcium in the body is found in body fluids.
Functions in body fluids include regulating ion transport across cell membranes, supporting muscle contraction, and aiding in hormone, enzyme, and neurotransmitter secretion. Calcium also helps maintain normal blood pressure and is essential for blood clotting.

Calcium and Disease Prevention

Calcium intake may help protect against hypertension (HTN).
Research suggests a potential protective relationship between calcium intake and diseases like diabetes, cholesterol levels, colon cancer, and osteoporosis.

Calcium Balance

Calcium regulation involves the kidneys, intestines, and bones.
Calcitonin and parathyroid hormone, along with vitamin D, also help regulate calcium levels.
High blood calcium can lead to calcium rigor.
Low blood calcium can lead to calcium tetany.

Calcium Absorption

Adults absorb ~30% of ingested calcium.
Children/teens absorb ~50-60% of ingested calcium.
Absorption can adjust based on need (e.g., pregnancy).
Factors that enhance absorption include stomach acid and vitamin D.
Factors that inhibit absorption include lack of stomach acid, vitamin D deficiency, high phosphorus intake, phytates (in seeds, nuts, grains), and oxalates (in beet greens, rhubarb, spinach, sweet potatoes).

Calcium Deficiency

Inadequate calcium intake prevents development of peak bone mass and density.
Osteoporosis is an adult bone loss condition characterized by brittle, fragile bones, increasing fracture risk.
It's often silent and not easily detected for some time.

Excess Calcium

Excessive calcium intake from supplements may negatively affect kidneys.
Kidney stones are associated with calcium accumulation in the kidneys.
Other contributing factors can include excess oxalates, phosphates, dehydration, and interference with other mineral absorption.

Calcium Recommendations

Recommended Daily Allowance (RDA) for calcium varies by age and sex.

Calcium Sources

Good sources include milk and milk products, vegetables (like rutabaga, broccoli, bok choy, and kale), small fish with bones, almonds, calcium-fortified foods (like plant-based milk, tofu, and OJ), and supplements.

A healthy diet with adequate calcium and vitamin D, along with regular physical activity (PA), may help achieve strong bones and reduce osteoporosis risk.
Vitamin D aids in calcium and phosphorus absorption and use in the body.

Phosphorus

Phosphorus is the second most abundant mineral in the body, with ~85% combined with calcium in hydroxyapatite crystals.
~15% is in soft tissues, such as muscles and kidneys.
Functions as part of genetic material, cell membranes (especially phospholipids), and energy transfer.

Phosphorus: Deficiency and Sources

Deficiency is rare, but if present, symptoms may include bone and muscle weakness.
Excess phosphorus can cause calcium excretion and kidney calcification.
Good sources include animal protein, cottage cheese, salmon, milk, steak, and navy beans.

Vitamin D

The body can synthesize vitamin D through sun exposure.
7-dehydrocholesterol in the skin absorbs UV light and converts to an inactive vitamin D3 precursor absorbed by the blood.
The liver and kidneys convert this precursor into the active 1,25-hydroxy vit D3 form.
Good sources include fortified milk, salmon, shrimp, and fortified soy beverages.

Factors Affecting Sun Exposure

Factors influencing sun exposure include air pollution (clouds, smog, smoke), buildings, window glass, window screens, clothing colors, lifestyle choices (homebound, shift work), skin pigmentation, seasonality, sunscreen use, time of day, and geographic location.

Vitamin D: Functions and Deficiency

Vitamin D helps absorb dietary calcium and phosphorus in the digestive tract, kidneys, and skeleton, maintaining bone integrity.
Vitamin D acts as a hormone and raises blood calcium levels when dietary calcium is insufficient.
Vitamin D affects bone and tooth health.
Deficiency is generally rare but can result in osteomalacia/Rickets.

Vitamin D: Excess and Sources

Taking doses that are 5x the recommended daily intake can cause toxicity; problems with over-supplementation and/or wrong fortification doses, can cause loss of appetite, nausea and vomiting, psychological depression, and increased blood calcium leading to calcium deposits in the heart, arteries, kidneys, brain, and bones.
Vitamin D is naturally found in eggs, fatty fish (e.g. salmon, sardines, mackerel), and fortified milk.
Recommendations and sources exist for plant-based diets.

Magnesium

Over half of the body's magnesium is stored in bones.
Almost all remaining magnesium is in muscle and soft tissues, except ~1% in extracellular fluids.
Functions include releasing energy, influencing calcium metabolism and vitamin D/K metabolism, and supporting normal muscle contraction and relaxation, nerve transmission and maintaining blood pressure by assisting in calcium regulation.
Magnesium help hold calcium in the enamel of teeth.

Magnesium: Sources, Deficiency, and Excess

Good magnesium sources include hard water, legumes, seeds (like pumpkin seeds), nuts, whole grains, leafy green vegetables, and seafood.
Deficiency symptoms may include weakness and muscle spasms (potentially fatal in the heart), convulsions, hallucinations, loss of appetite, and confusion.
Excess intake, often from supplements or antacids, may cause diarrhea, dehydration, and acid-base imbalances.

Fluoride

Fluoride helps form more decay-resistant hydroxyapatite in teeth and bones.
Fluoride acts directly on bacteria in dental plaque, slowing metabolism and reducing acid production.
Good sources of fluoride include fluoridated tap water, seafood (varying concentrations).

Fluoride: Deficiency, Excess, and Recommendations

Deficiency in fluoride can lead to tooth decay and dental caries.
Excess fluoride can cause fluorosis—irreversible discoloration of the teeth.
Recommendations for fluoride intake vary by age.

Vitamin K

Vitamin K plays a role in bone health.
It's necessary for synthesizing proteins needed in bone formation, particularly osteocalcin.
Adequate vitamin K helps decrease bone turnover and prevent fractures, working alongside Vitamin D and Calcium to promote proper bone formation.

Osteoporosis & Calcium Highlights

Osteoporosis, a condition involving brittle, fragile bones, is significantly associated with insufficient calcium intake and decreased bone mineral density.

Development of Osteoporosis

The incidence of osteoporotic fractures is significant, affecting 1 in 3 women and 1 in 5 men during their lifetime.
Healthcare systems bear a significant burden due to repair and hospital stay costs.

Risk Factors and Protective Factors for Osteoporosis

Non-modifiable factors include age, gender, ethnicity, and maternal history, while modifiable factors involve lifestyle, such as physical activity, calcium/vitamin D intake, smoking, and body weight.

Age and Bone Calcium

Bone mass typically decreases with age, particularly after menopause in women.

Gender and Hormones

Sex hormones play a crucial role in bone turnover, particularly estrogen in women, with its decline during menopause presenting as a risk factor.
Men also experience lower bone mass with age, potentially relating to testosterone levels.

Other Contributing Factors

Genetic predisposition and environmental factors affect bone mass and rate of loss later in life.
Physical activity, especially weight-bearing exercises, strengthens bones and increases density.
Body weight and weight loss, along with smoking and alcohol use, can affect bone density.

Bone Growth Goals

Different stages of life (childhood, adolescence, adulthood) have different recommendations for maintaining and/or growing bone mass/density.
This relates to consumption habits of critical vitamins and minerals like Ca, Vitamin D, and weight-bearing activities.

Calcium Supplements

If dietary sources for sufficient calcium, consult with a healthcare professional to avoid exceeding the upper limit (UL) or suffering from excess in the body.
Multivitamins may have some levels of calcium, but avoid mixing with other supplement or foods high in iron, as they may contain interfering components that lead to poor absorption.

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Description

This quiz explores the essential role of calcium in maintaining blood pressure, bone health, and its absorption in the body. It also delves into dietary recommendations and the impact of vitamin D and magnesium on skeletal health. Test your knowledge on these important topics related to nutrition and bone density.