NUTR 202: Module 3

What is the general function of vitamins and minerals (as compared to macronutrients)?

• Not energy yielding

• Involved in metabolic processes

• Assist in providing energy

Vitamins: Organic

Minerals: Inorganic

Be able to identify fat soluble vs. water soluble vitamins.

Fat soluble vitamins:

• Storage in body

  • Longer periods of time

  • Larger amounts

  • Found in liver and fat cells

  • INCREASE likelihood of adverse effects or toxicity

Water soluble vitamins:

• Storage in body

  • Short period of time

  • not generally stored in large quantities

  • DECREASED likelihood of toxicity, BUT INCREASED risk of deficiency

fat soluble vitamins

• Vitamin A

• Vitamin D

• Vitamin E

• Vitamin K

water soluble vitamins

• Vitamin C

• Thiamin

• Riboflavin

• Niacin

• Biotin

• Folate

What are the functions of Vitamin A?

• Integrity of epithelial cells

• Bone growth

• Cell membrane stability

• Gene Regulation

  • CELL DIFFERENTIATiON

• Vision

  • Crucial to normal vision

• Immune function

  • Disease resistance, particularly for children

  • Production of white blood cells

Occurs in 3 different forms:

1. Retinol (most active form)—> stored in liver

2. Retinal

3. Retinoic acid

Vitamins may be added to foods, but are not naturally present in food

Fortified

Vitamins may be lost during processing and added back to meet needs

Enrichment

What are the differences between preformed vitamin A and provitamin A?

Preformed vitamin A:

• Ready to use

  • Found in animal-based or fortified foods

Provitamin A:

• Converted to active form as needed

  • Ex: beta-carotene

    • Found in plant-based foods

Identify dietary sources of preformed vitamin A and provitamin A.

Preformed Vitamin A:

• Fortified milk, cheese, cream, butter, eggs, liver

Provitamin A:

• Green leafy vegetables, Orange and red produce, apricots, cantaloupe, carrots, sweet potatoes, and pumpkins

Describe deficiency and toxicity symptoms associated with vitamin A.

Early stages of deficiency:

• Night blindness

  • Reversible

Short-term vitamin A deficiency:

• The cornea becomes dry and damaged

Long-term vitamin A deficiency:

• Xerophthalmia— which prevents the eyes from producing necessary tears, causing extreme dryness, damage to the cornea, and potential blindness.

• Permanent loss of vision

Toxicity: (if stored in body for long periods of time)

• Liver damage

• Birth defect

• Iron and Vitamin A deficiency may coexist

What is the role of vitamin D in calcium metabolism?

• Stimulates cells of small intestine to produce calbindin

  • A calcium binding protein

  • INCREASES calcium absorption

• Stimulates kidneys to conserve calcium

  • DECREASES urinary calcium excretion

• Stimulates calcium release from bone to help maintain blood calcium levels

What are potential reasons for increased vitamin D needs in older adults?

• Ability to convert Vitamin D into is active form DECREASES

• Likelihood of adequate exposure to sunlight DECREASES

Identify dietary and non-dietary sources of vitamin D.

Dietary sources of vitamin D:

• Cod liver oil

• Sardines, salmon, shrimp

• Liver

• Mushrooms exposed to UV light

  • FORTIFIED foods provide MAJORITY of dietary vitamin D

    • Milk or margarine

    • Cereals

    • Juices

    • ******NOT CHEESE AND YOGURT

Non-dietary sources:

Human body makes vitamin D w/ adequate exposure to sunlight through a series of steps

1. Cholesterol in skin combines w/ UV rays

2. Converted into precursor of vitamin D

3. Eventually makes its way to the kidneys

• Converted to active form of D3

What chronic condition(s) is/are associated with insufficient vitamin D levels?

Children:

• **Rickets

  • Disease characterized by softening and deformity of long bones

  • Inability to deposit calcium in newly formed bone

  • Malformation of the skull, ribcage, and ends of long bones

Adults:

• **Osteomalacia

  • Softening of bone caused by decalcification

What population(s) is/are at risk of Vitamin D insufficiency?

• Ethnic populations w/ dark skin

• Land caucasian population

What are the primary functions of Vitamin E?

• Acts as an **antioxidant

  • Neutralize free radicals that can damage cell membranes, DNA, proteins

    • Unstable compounds w/ unpaired electron that attack other molecules

      • Vitamin E donates electron to neutralize free radicals!!

• Enhances immune function

• Required for nerve cell development

What population is at greatest risk for Vitamin E deficiency

• Premature infants

• Insufficient stores

  • Can result in Anemia**:

    • Due to red blood cell fragility and subsequent rupture

What are the primary functions of vitamin K?

• Blood clotting

• Activates proteins required to make:

  • Fibrin

    • Forms blood clots

• Also required for synthesis of bone protein

  • Osteocalcin

  What population is at greatest risk for K deficiency?

• Newborns

  • Relatively sterile GI tract at birth (bacteria is a non-food source and is the most significant source of Vitamin K in humans)

  • Breast milk is a poor source of vitamin K

  • Single dose of vitamin K given at birth!

• Prolonged use of antibiotics

List the functions of vitamin C.

• Acts as an antioxidant

  • Immune system health

• Synthesis of collagen

  • Protein that forms connective tissue of tendons, bone, teeth, and skin

    • Functions of collagen:

      • Wound healing

      • Maintenance of blood vessel structure

• Facilitates iron absorption in GI

What condition is caused by Vitamin C deficiency?

• Scurvy

  • Severe deficiency

  • Improper formation of collagen

• Anemia

  • Due to poor iron absorption

• Signs of deficiency include:

  • Bleeding gums, loss of appetite, small hemorrages on skin, weakness

  What are 3 dietary sources of Vitamin C?

• Orange juice (best source)

• Limes, lemons

• Kiwis

• Red bell peppers

• Strawberries

• Sweet potatoes, brussel sprouts

Describe the primary deficiency conditions associated with thiamin
(B1), niacin (B3), folate (B9) and vitamin B12.

Thiamin Deficiency:

• Occurs in malnourished individuals and alcoholics

  • Beriber**

    • Heart becomes enlarged, fluid accumulates in skin and muscles weaken/atrophy

    • If condition affects CVD system:

      • ****WET beriber

    • If condition affects Nervous system:

      • **DRY beriber

    • SEVERE DEFICIENCY IN ALCOHOLICS —→ Wernicke-Karsokoff Syndrome

Niacin B3:

• Pellagra

  • Symptoms referred to as “the Fours Ds”

    • Diarrhea, dermatitis, dementia, death

Folate B9:

• Inability to synthesize DNA during folate deficiency

• Results in large, immature red blood cells that are fewer in number:

  • **Macrocytic anemia

Vitamin B12:

• Macrocytic anemia

• If due to lack of intrinsic factor:

  • Pernicious anemia

List the primary functions of vitamin B12 and folate.

Folate

• Cell division

  • DNA replication requires folate during cell division

• AffectsL

  • Red blood cell synthesis

  • Central nervous system formation during fetal development

Vitamin B12

• Essential in converting folate into active form

• Maintains the insulating lining that covers nerve fibers known as”

  • **Myelin shealth

• Vitamins B12 and folate are important for homocysteine metabolism

  • High levels of homocysteine (AA) in blood = increased risk of CVD

Identify dietary sources of vitamin B12, folate, and folic acid.

Vitamin B12

• Milk, cheese, meat (especially organ meats), poultry and seafood

• Ready to eat cerals, soy products, supplements

Folate (naturally occuring form)

• Orange juice, green leafy veggies, legumes, tomato juice, asparagus

Folic acid (synthetic form, easier to absorb in GI)

• Supplements, enriched grains

Identify the toxicity condition associated with niacin.

• One of the few water-soluble vitamins to have toxicity symptoms

• Overconsumption of supplements or fortified foods

  • **”Niacin flush

    • Overconsumption of 3x to 4x RDA

    • Redness of face, arms, and legs

    • Temporary condition

  • High doses of nicotinic acid prescribed for cholesterol reduction results in niacin flush

    • **Liver injury

a.      Describe the process of vitamin B12 absorption.

• i.   When B12 is consumed from food, what must happen first in
  the stomach so that B12 can eventually be absorbed?

• ii) What protein is required for B12 absorption?

ccc

 Identify individuals at risk for vitamin B12 deficiency and describe
why these individuals are at risk.

c

Describe the differences between macrominerals and microminerals.

v

Describe the process of blood calcium regulation when blood calcium becomes low.

v

What are the functions of calcium in the body?

v

Identify at least 3 good dietary sources of calcium.

v

List 3 modifiable and 3 non-modifiable risk factors for osteoporosis.

c

What are the primary functions of magnesium, phosphorus and sulfur in the body?

c

Identify 3 dietary sources of magnesium.

c

What minerals are involved with bone health?

v

What is the primary storage form of sulfur in the body?

c

Identify the role of iron in the body.

c

List the type of food sources (ie. animal or plant) that contain heme vs. non-heme iron.

c

Describe absorption of iron in the body.

v

What factors can increase and what factors decrease iron absorption?

v

What form of iron is most easily absorbed?

v

Identify individuals with increased iron requirements.

v

Identify the leading nutrient deficiency worldwide.

c

What are potential causes of anemia?

v

List the blood tests used to screen for anemia. Which is the most sensitive to low iron stores?

c

What is the condition associated with iron toxicity? What is the cause of this condition?

c

What factor(s) hinder zinc absorption and what factor(s) enhance zinc absorption?

d

What are two symptoms of zinc toxicity and deficiency.

v

Identify the primary function of copper in the body.

v

What other mineral may hinder copper absorption?

v

What is the primary role of iodine in the body?

c

What may occur if an individual becomes iodine deficient?

v

List 2 common dietary sources of iodine.

v

What is the primary function of selenium in the human body?

v

What is the primary function of selenium in the human body?

v

Can an individual consume too much fluoride? If so, what condition may develop?

vv

What population group may be recommended to take a chromium supplement? Why might this population take supplemental chromium?

List the two federal agencies involved in regulating supplements and supplement claims and labeling.

c

  Identify populations in which dietary supplement use is most prevalent.

v

Describe steps involved in making an informed decision about taking dietary supplements.

c

Do doctors recommend beta-carotene for the general public?

NO

Is vitamin D toxicity common?

NO, toxicity is NOT common

• Occurs from overuse of supplements

What factors influence vitamin D synthesis?

• Distance from equator

• Amount of clothing coverage on body

• Sun block use

• Cloud cover or smog

• Age

• Skin color

Is there an increased need for vitamin C in smokers?

YES

Describe the primary deficiency conditions associated with thiamin
(B1)

• Occurs in malnourished individuals and alcoholics

• Beriber**

  • Heart becomes enlarged, fluid accumulates in skin and muscles weaken/atrophy

  • If condition affects CVD system:

    • ****WET beriber

  • If condition affects Nervous system:

    • **DRY beriber

  • SEVERE DEFICIENCY IN ALCOHOLICS —→ Wernicke-Karsokoff Syndrome

Describe the primary deficiency conditions associated with Niacin B3

• Pellagra

  • Symptoms referred to as “the Fours Ds”

    • Diarrhea, dermatitis, dementia, death

Describe the primary deficiency conditions associated with Folate B9

• Inability to synthesize DNA during folate deficiency

• Results in large, immature red blood cells that are fewer in number:

  • **Macrocytic anemia

Describe the primary deficiency conditions associated with Vitamin B12

• Macrocytic anemia

• If due to lack of intrinsic factor:

  • Pernicious anemia