Nutrition Chapter 10

What are the B vitamins?

B1 (Thiamin)

B2 (Riboflavin)

B3 (Niacin)

B5 (Pantothenic acid)

B6 (Pyridoxine)

B7 (Biotin)

B9 (Folate)

B12 (Cobalamin)

What is the main role of B vitamins?

Act as coenzymes in energy metabolism

What do B vitamins help produce?

ATP (energy) from carbohydrates, fats, and proteins

Do B vitamins provide energy directly?

No — they do not contain calories

What is their key role instead?

Help convert macronutrients into energy

Where are B vitamins commonly found besides food?

Energy drinks and supplements

Where does the "energy" in energy drinks actually come from?

Stimulants like caffeine

What is the function of thiamin?

Coenzyme for converting carbohydrates and fats into ATP

How was thiamin discovered?

Through polished rice deficiency (removal of bran/germ)

What disease is caused by thiamin deficiency?

Beriberi

Symptoms of beriberi?

Fatigue

Paralysis

What are sources of thiamin?

Whole grains

Enriched grains

Pork

What is the function of riboflavin?

Coenzyme for converting carbohydrates and fats into ATP

What additional role does riboflavin have?

Part of antioxidant enzyme system

What does riboflavin help protect against?

Free radicals

What are sources of riboflavin?

Meat

Milk

Enriched grains

What are other names for niacin?

Nicotinamide

Nicotinic acid

What is the function of niacin?

Coenzyme for converting carbohydrates and fats into ATP

What disease is caused by niacin deficiency?

Pellagra

What are the 4 D's of pellagra?

Dermatitis

Diarrhea

Dementia

Death

What are sources of niacin?

Meat

Fish

Poultry

Enriched grains

What are the main functions of folate?

DNA synthesis

Amino acid metabolism

Reduces CVD risk (↓ homocysteine)

Red blood cell production

Critical for cell division (especially embryos)

Why is folate important for cardiovascular health?

Helps lower homocysteine levels

What are good sources of folate?

Leafy green vegetables

Enriched grains/cereals

Beef liver

Spinach

Black-eyed peas

White rice

What happens if folate is over consumed?

Excess is excreted (water-soluble)

Can mask vitamin B12 deficiency

What happens if folate is deficient?

Macrocytic anemia

Increased CVD risk

Neural tube defects

Why is folate critical during pregnancy?

Needed for rapid cell division and neural tube formation

What is the recommended folate intake during pregnancy?

~600 mcg/day (vs 400 mcg normally)

When is folate most critical in pregnancy?

First 4 weeks

What does the neural tube develop into?

Brain and spinal cord

If a pregnant woman does not consume enough folate during the first 4 weeks of pregnancy, the risk for ____________________ is increased.

Neural tube defects

What is spina bifida?

this is a birth defect in a child, which can cause muscle weakness of the legs and sometimes lead to paralysis. They may also experience bowel and bladder problems, have seizures, or have orthopedic problems such as deformed feet, uneven hips, or a curved spine (scoliosis)

What type of nutrient is iodine?

Trace mineral

What is the main function of iodine?

Needed to produce thyroid hormones

What do thyroid hormones regulate?

Body temperature

Growth

Metabolism (RMR)

What are common sources of iodine?

Iodized salt

Saltwater fish

Shrimp

Dairy

Eggs

Main source of iodine in the U.S.?

Iodized salt

What happens if iodine intake is too high?

Blocks thyroid hormone production

Can cause goiter (enlarged thyroid)

What happens if iodine intake is too low?

Hypothyroidism

Symptoms of iodine deficiency?

Goiter

Fatigue

Weight gain

What is cretinism?

Developmental disability from iodine deficiency during pregnancy

What are the main functions of blood?

Transports oxygen and nutrients to cells

Removes waste from cells

What are the main components of blood?

Leukocytes (WBCs)

Platelets

Erythrocytes (RBCs)

What do leukocytes do?

Immune system function

What do platelets do?

Help with blood clotting

What do erythrocytes do?

Transport oxygen using hemoglobin

What is anemia?

Low hemoglobin levels

How common is anemia worldwide?

~2 billion people affected

750,000 deaths a year in africa and southeast asia are from anemia

What are common causes of anemia?

Nutritional deficiencies

Infections

Hemoglobin disorders

What causes macrocytic anemia?

Low folate or vitamin B12

What happens in macrocytic anemia?

RBCs are large

Poor DNA synthesis

Less hemoglobin

Symptoms of macrocytic anemia?

Weakness

Fatigue

Poor concentration

Irritability

Headache

Shortness of breath

What causes microcytic anemia?

Low iron, copper, or vitamin B6

What happens in microcytic anemia?

RBCs are small

Low hemoglobin

Symptoms of microcytic anemia?

Fatigue

Pale skin

Poor performance

Weak immune function

Memory issues

What are the functions of vitamin B12?

DNA synthesis

Blood formation

Nerve function

What are sources of vitamin B12?

Meat

Fish

Poultry

Dairy

Eggs

Liver/kidneys

Fortified cereals and plant milks

Nutritional yeast

Where is vitamin B12 typically found vs vitamin E?

B12 → animal foods

Vitamin E → plant foods

What causes vitamin B12 deficiency?

Low intake

Low stomach acid (HCl)

Lack of intrinsic factor

Why is stomach acid important for B12?

It releases B12 from food

What is pernicious anemia?

Anemia caused by lack of intrinsic factor → poor B12 absorption

What type of anemia is caused by B12 deficiency?

Macrocytic anemia

Symptoms of B12 deficiency?

Fatigue

Pale skin

Low energy

What neurological issues occur with B12 deficiency?

Nerve damage (myelin loss)

Poor coordination

Numbness/tingling in hands and feet

What type of nutrient is iron?

Trace mineral

What are the main functions of iron?

Helps metabolize carbs, fats, and proteins (energy)

Supports immune function

Part of antioxidant enzyme system

Component of hemoglobin and myoglobin

What is the role of iron in hemoglobin?

Binds oxygen so it can be transported in the blood

Where is most iron found in the body?

~⅔ in hemoglobin

What is myoglobin?

Protein that carries oxygen in muscle cells

How is iron stored in the body?

As ferritin or hemosiderin

Where is iron stored?

Liver

Bone marrow

Intestinal mucosa

Spleen

What lab value indicates iron storage levels?

Ferritin

How much of our daily iron needs come from recycling RBCs?

~90%

How much iron is absorbed in a typical diet?

~18% (mixed diet)

1-10% (vegan diet)

What factors affect iron absorption?

Iron status (inverse)

Stomach acid (direct)

Amount of iron intake

Other dietary factors

What decreases iron absorption?

Phytates

Polyphenols

Soy protein

Calcium

What are the two types of iron?

Heme (animal sources)

Non-heme (plant sources)

Which type of iron is better absorbed?

Heme iron

How can non-heme iron absorption be improved?

Eat with vitamin C

Eat with animal protein ("meat factor")

What is a risk of high heme iron intake?

Increased risk of cardiovascular disease

What are good sources of iron?

Meat, fish, poultry

Clams, oysters

Enriched grains

Lentils, spinach

How can cooking methods increase iron intake?

Cooking in cast iron cookware

What is the RDA for iron?

~8-18 mg/day

Which of the following individuals will absorb the greatest percent of iron that is consumed?

Henrik a cross country skier who consumes 50% of the DRI for iron each day

Leonid, a rugby player, struggles to maintain his iron levels in his body and wants to know how to increase the absorption of the iron that he does eat. Which of the following would be the best advice to give Leonid?

Add some animal based iron sources, such as red meat in order to consume more heme iron, which is absorbed more readily than non-heme iron

What happens if too much iron is consumed?

Iron toxicity (overdose)

Symptoms of iron toxicity?

Nausea

Vomiting

Diarrhea

Dizziness

Confusion

Rapid heart rate

What can severe iron toxicity cause?

Damage to heart, liver, kidneys, CNS, and death

What is hemochromatosis?

Genetic condition causing excessive iron absorption

What are risks of hemochromatosis?

Organ damage

Cancer

Irregular heartbeat

Cirrhosis

What is the most common nutrient deficiency worldwide?

Iron deficiency

Who is at highest risk for iron deficiency?

Infants

Young children

Adolescent girls

Menstruating women

Pregnant women

What happens in iron deficiency anemia?

Low hemoglobin

What does low hemoglobin lead to?

Reduced oxygen delivery → fatigue

When someone has developed anemia, what do they have difficulty making enough of?

hemoglobin

As a result of not making enough of the entity in the previous question, the delivery of what to the body is compromised? What is the main symptom that results?

Oxygen, fatigue

How common is iron deficiency anemia during pregnancy?

1 in 6 pregnant women will have iron deficiency or iron deficiency anemia

Women need 18 mg of iron/day. How much more is needed during pregnancy? What

percent increase is this?

27 mg are needed during pregnancy a 50% increase

What type of vitamin is vitamin K?

Fat-soluble

What is the main function of vitamin K?

Coenzyme for proteins involved in blood clotting