Fat soluble Vitamins Lecture Review

Comprehensive vocabulary flashcards covering general vitamin properties, fat-soluble vs. water-soluble characteristics, and specific roles, deficiencies, and toxicities of Vitamins A, D, E, and K.

Vitamins

Organic micronutrients that do not provide energy, are needed in trace amounts ($\text{micrograms}$ or $\text{milligrams}$), and perform specific functions for growth, reproduction, and health maintenance.

Fat-Soluble Vitamins

Vitamins (A, D, E, and K) that are absorbed into the lymph and then the blood, travel with protein carriers, and are stored in the liver or fatty tissue.

Water-Soluble Vitamins

Vitamins (B-vitamins and Vitamin C) absorbed directly into the blood that travel freely and are readily excreted in the urine, requiring frequent doses.

Bioavailability

The amount of a vitamin absorbed and used by the body, which depends on the quantity provided and factors like digestion efficiency and food preparation.

Precursors

Inactive forms of vitamins available from foods that are converted into the active form once inside the body.

Vitamin A (Retinoids)

A fat-soluble vitamin occurring in three active forms: Retinol, Retinal (retinaldehyde), and Retinoic Acid.

Retinoic Acid

The form of Vitamin A that regulates gene expression, influencing protein synthesis and metabolic activities.

Beta-Carotene

An extremely effective antioxidant and precursor to Vitamin A; excessive intake can impart a yellowish color to the skin.

Keratin

A hard, inflexible protein found in hair and nails that is produced by epithelial cells when Vitamin A is deficient, potentially leading to blindness.

Teratogenic risk

The risk of abnormal fetal development and birth defects associated with Vitamin A toxicity during pregnancy.

Retinol Activity Equivalents (RAE)

A measure of the amount of retinol the body derives from plant foods; the body can make 1 unit of retinol from 12 units of beta carotene.

Free Radicals

Compounds formed by oxygen that can start chain reactions in cell membranes, damaging structures and contributing to diseases like cancer and aging.

Vitamin D

A hormone synthesized in the skin via sunlight (UVB) that assists in the absorption of Calcium and Phosphorous for bone maintenance.

Rickets

A Vitamin D deficiency disease in children where bones fail to calcify normally, leading to skeletal abnormalities like bowed legs.

Osteomalacia

A condition characterized by the loss of calcium from the bones, typically due to Vitamin D deficiency.

Vitamin D Toxicity

Condition where excess Vitamin D raises blood calcium concentrations, leading to stone formation in kidneys and calcification of blood vessels.

$$\text{Alpha-tocopherol}$$

The gold standard for Vitamin E activity among the various tocopherols and tocotrienols.

Erythrocyte Hemolysis

The breaking open of red blood cells caused by oxidation of polyunsaturated fatty acids when Vitamin E concentrations are too low.

Vitamin K

A fat-soluble vitamin essential for blood clotting and the synthesis of bone proteins; it can be synthesized by bacteria in the intestinal tract.

Prothrombin

An inactive protein precursor of the enzyme thrombin that requires Vitamin K for activation during the blood clotting process.

Fibrin

The final solid clot formed during the blood clotting process following the activation of thrombin and fibrinogen.

Hemorrhagic disease

A condition resulting from a lack of blood clotting factors, such as Vitamin K deficiency.

B-vitamins

Thiamin, Riboflavin, Niacin, Pantothenic acid, Biotin, Vitamin B6, Vitamin B12, Folate (B9)

What are precursors in relation to vitamins?

Inactive forms of vitamins available from foods that are converted into the active form once inside the body.

How can you minimize vitamin loss in food?

• Refrigeration: Slows down loss by enzymatic action.

• Storage in opaque containers: Protects from light and air.

• Avoid high temperatures: Prevents heat destruction or losses in water while cooking.

What are the roles of Vitamin A?

• Gene Expression: Retinoic acid regulates hundreds of genes, directing the synthesis of proteins, including enzymes, influencing metabolic activities and overall health.

• Vision: Maintains a healthy cornea and aids in light detection at the retina; deficiency leads to difficulty adapting to changing light levels.

• Skin and Lining of Organs: Promotes protein synthesis and cell differentiation.

-Gene Regulation in Immunity: Regulates genes involved in immune response; a deficiency alters response to infection, weakening the body's defenses.

• Reproduction and Growth: Crucial for sperm development in men and promotes normal fetal growth and development in women.

• Fetal Development: Transferred to the fetus during pregnancy, supporting the development of the nervous system, lungs, heart, kidneys, skeleton, eyes, and ears.

• Beta-Carotene: Acts as an extremely effective antioxidant.

What are the effects of Vitamin A deficiency?

• Impaired Cell Differentiation and Maturation: Epithelial cells flatten and begin to produce keratin (a hard, inflexible protein), leading to hardening of the cornea, which may progress to blindness.

• Skin Changes: Cells of the skin harden, resulting in dry, rough, scaly, and hard skin.

• Mouth Effects: Hardening of the salivary glands makes them susceptible to infections.

• Digestive Issues: Reduced secretion of mucus in the stomach and intestine.

What are the effects of Vitamin A toxicity?

• Overdose Risks: Damages the same body systems that exhibit symptoms of deficiency.

• Teratogenic Risk: Associated with abnormal fetal development and birth defects during pregnancy.

• Bone Health: Excessive amounts over the years may weaken bones, contributing to fractures and osteoporosis.

• Recommended Dietary Allowance (RDA): 700 µg for men; 900 µg for women.

What are measuring units for vitamins?

• International Unit (IU): Depends on each substance; it is not a standard.

• Metric Measurement:

  1. 1 Kilogram = 1000 grams

  2. 1 Gram = 1000 milligrams (mg)

  3. 1 Milligram = 1000 micrograms (µg)

• Specific Measurements for Vitamin A:

  • 1 IU = 0.3 µg retinol

  • 1 IU = 0.5 µg beta-carotene

What is the role of Vitamin A as an antioxidant?

• Protection from Oxygen Attack: Vitamin A protects cells from attack by oxygen, which triggers the formation of compounds known as free radicals.

• Free Radical Reactions: Free radicals can start chain reactions in cell membranes; if left uncontrolled, these reactions can damage cell structures and impair cell functions.

• Health Implications: Free radical damage to cells instigates early stages of diseases such as cancer, heart disease, Alzheimer’s, arthritis, cataracts, diabetes, kidney disease, and is responsible for aging.

What are Retinol Activity Equivalents (RAE)?

• Definition: RAE represents the amount of retinol the body derives from plant foods after conversion.

• Conversion Rate: The body can make 1 unit of retinol from 12 units of beta carotene.

What is Beta-Carotene and its excess effects?

• Beta-Carotene: An extremely effective antioxidant and precursor to Vitamin A.

• Excess Intake: Builds up in the fat just beneath the skin and imparts a yellowish color, indicating excess beta carotene.

What are the effects of Vitamin D deficiency?

• Prevalence: Almost 10% of the population is deficient in Vitamin D, with another 25% being marginally deficient.

• Contributing Factors: Dark skin, breastfeeding, and lack of sunlight exposure contribute to deficiency.

• Rickets Disease: Primarily observed in regions like Mongolia, Tibet, and the Netherlands; rarely seen in the U.S. Rickets causes bones to fail to calcify normally, leading to growth retardation and skeletal abnormalities. The bones become weak and may bend, causing bowed legs.

• Concern in Youth: Indoor activities, such as playing computer games, reduce exposure to sunlight, increasing deficiency risks.

• Osteomalacia: Characterized by the loss of calcium from bones.

• Osteoporosis: Results in reduced bone density, increasing the likelihood of fractures later in life.

What is the relationship between sun exposure and Vitamin D production?

• Sun Exposure: About 10 to 20 minutes of sun exposure can produce approximately 3,000 IU of Vitamin D.

What is Alpha-Tocopherol?

• Definition: The gold standard for Vitamin E activity among the various tocopherols and tocotrienols.

What is Vitamin E?

• Function: Acts as an antioxidant, helping to protect cells from oxidative damage.

• Alpha-Tocopherol: The most active form of Vitamin E in humans and considered the gold standard for Vitamin E activity.

• Sources: Found in foods like nuts, seeds, and green leafy vegetables.

• Deficiency: Can lead to problems such as and immune dysfunction. Erythrocyte Hemolysis, Hemolytic Anemia: too few red blood cells as a result Loss of muscle coordination and reflexes with impaired movement, vision, and speech (Vitamin E corrects all these symptoms) Deficiency occurs after years of eating diets extremely low in fat.

• Toxicity: Generally considered low risk, but excessive amounts could interfere with blood clotting.

What is the Recommended Dietary Allowance (RDA) for Vitamin E in adults?

• RDA: The Recommended Dietary Allowance (RDA) for adults is 15 mg per day of Vitamin E.

What are some sources of Vitamin E and their amounts?

• 1/4 cup oil roasted almonds: Provides 10 mg of Vitamin E.

• 1/4 cup blanched hazelnuts: Provides 5.25 mg of Vitamin E.

• 1 tablespoon of canola oil: Provides 2.37 mg of Vitamin E.

• Conversion: 1 IU = 0.45 mg of dl alpha-tocopherol acetate.

What are the roles of Vitamin K?

• Essential for Blood Clotting: Vital for the activation of at least 13 different proteins involved in making blood clots.

• Prothrombin Activation: Necessary for the conversion of prothrombin, the precursor of the enzyme thrombin, which plays a critical role in the blood clotting process.

What is Vitamin K toxicity?

• Vitamin K Toxicity: It is rare, and no adverse effects have been reported; therefore, the Tolerable Upper Intake Level (U.L) has not been established.

• Adequate Intake (A.I): 120 µg/day for men and 90 µg/day for women.

What are some food sources of Vitamin K?

• Green leafy vegetables: Such as kale, spinach, and broccoli.

• Brussels sprouts: A great source of Vitamin K.

• Fish: Certain types of fish are high in Vitamin K.

• Meat: Includes beef and chicken, which provide Vitamin K

• Dairy products: Can contain Vitamin K as well.\n

• -Fermented foods: Such as natto, which is particularly rich in Vitamin K