Ch. 9 Fat Soluble Vitamins: Characteristics

Study Notes

Vitamins: Definition and Functions

Tasteless, organic compounds required in small amounts for various body functions.
Regulate metabolism and convert energy from fats, carbohydrates, and proteins into ATP.
Promote growth and reproduction; deficiencies can lead to serious health issues.
Excess intake of certain vitamins can be toxic.

Vitamin Classification

Vitamins are grouped based on solubility into:
- Nine water-soluble vitamins: B vitamin complex and Vitamin C.
- Four fat-soluble vitamins: Vitamins A, D, E, and K.

Influence of Solubility

Solubility affects:
- Digestion, absorption, transportation, storage, and excretion of vitamins.

Absorption and Storage Differences

Both fat-soluble and water-soluble vitamins are absorbed in the small intestine.
Fat-soluble vitamins require fat for absorption and can accumulate in the body, potentially leading to toxicity.

Fat Soluble Vitamins Characteristics

Released from food with proteins in the stomach and absorbed in the duodenum, then transported via lymph into the bloodstream.
Stored mainly in the liver (Vitamin A) or fat/muscle tissue (Vitamin D) but can accumulate to toxic levels.

Water Soluble Vitamins Characteristics

Absorbed along with water directly into the bloodstream, predominantly in the duodenum and jejunum.
Not stored; excesses are excreted in urine, necessitating daily intake.

Vitamin Stability During Cooking/Storage

Vitamins can be destroyed by exposure to oxygen, light (especially UV), water, heat, changes in pH, and during the preservation of fruits and vegetables.
Fat-soluble vitamins tend to be more stable compared to water-soluble vitamins.

Antioxidants

Compounds that neutralize free radicals to counteract cellular oxidation.
Includes Vitamin E (fat-soluble), Vitamin C (water-soluble), selenium (mineral), flavonoids, and carotenoids.

Free Radicals

By-products of metabolic reactions, unstable molecules with unpaired electrons.
Caused by UV light, smoking, and environmental pollutants.

Dangers of Free Radicals

Accumulation leads to oxidative stress, damaging DNA and proteins, affecting cell structure.
Contributes to chronic diseases such as heart disease, diabetes, Parkinson's, Alzheimer's, cancer, and aging.

Oxidation Processes

Some free radical damage is preventable, while certain oxidative stress is inevitable due to natural aging and environmental factors.

Role of Antioxidants in Health

Antioxidants, including certain phytochemicals, also stimulate the immune system and may prevent cancer.
They are primarily found in plant foods and believed to offer more health benefits than supplements.

Importance of Dietary Sources

Emphasis on obtaining vitamins and antioxidants from food sources rather than supplements for optimal health benefits.

Description

Explore the essential characteristics and classifications of fat soluble vitamins through detailed flashcards. Learn about their roles in metabolism, energy conversion, growth, and reproduction, along with the impact of deficiencies and excesses. Perfect for understanding vitamin dynamics in health.

Ch. 9 Fat Soluble Vitamins: Characteristics

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Questions and Answers

What are vitamins?

Vitamins play an unimportant role in maintaining health.

In what groups do vitamins work?

How many water-soluble vitamins are there?

Which vitamins are classified as fat-soluble?

What influences a vitamin's solubility?

Fat-soluble vitamins are absorbed directly into the bloodstream.

Where is Vitamin A mainly stored?

What happens to excess water-soluble vitamins?

Vitamins can be destroyed during cooking or storage.

What are free radicals?

Which of the following are considered antioxidants?

What are the dangers of free radicals?

Match the following antioxidants with their sources:

Phytochemicals are synthetic compounds.

Why are vitamins found widely in food groups important?