Chapter 9: Vitamins

03/13/2025- Started flashcard set ~X

Are vitamins organic? do they offer energy?

Yes, but they do not offer energy.

How are vitamins classified?

Classified into fat- soluble (hydrophobic, water fearing) or water-soluble (hydrophilic, water loving).

where do water-soluble vitamins act in the body?

act in the cytosol of cells or in extracellular fluids such as blood.

where do fat-soluble vitamins act in the body?

act responsibly for protecting cell membranes from free radical damage.

What are unique characteristics of vitamins?

• Exist as individual units

• Do not yield energy

• readily available in food (fresh fruits, vegetables, dairy and meats)

• Measured in very small quantities- mcg or mg.

Is there such thing as essential and non-essential vitamins?

yes

if a diet lacks certain vitamins, what can occur?

vitamin deficiencies.

Do vitamin get digested?

No they do not, they are taken in as is.

classifications of fat soluble vitamins

• Absorbed with dietary fat (into lymph)

• Often in fatty foods, but not always

• Can accumulate in adipose tissue

• Toxicity may result

• Vitamins A, D, E, K (A Dumb Elephant Knows when its fat)

Classifications of water soluble vitamins

• Easily absorbed into blood

• Excess is excreted in urine

• B vitamins, vitamin C, and Choline (though choline is not a vitamin) (BCC)

Vitamin intake is measured in very small amounts. what are they?

• 1 gram= 1 paper clip

• 1 milligram (mg)= 1/1,000 of a paper clip

• 1 microgram (mcg)= 1/1,000,000 of a paper clip

Why do we need such small amounts of vitamins intake?

Because vitamins are reusable.

What are the general functions of vitamins?

• Energy metabolism

• Blood components and clotting

• Bone health

• Antioxidants

• Vision

Which vitamins are important in energy metabolism?

• Vitamin B-1 (Thiamin)

• Vitamin B-2 (Riboflavin)

• Niacin

• Pantothenic acid

• Vitamin B-6 (pyridoxine)

• Vitamin B-12 (cobalamin)

• Folate

• Biotin

Bioavailability

The amount of vitamin absorbed and used by the body

Fat-soluble vitamins and water-soluble vitamins differ in the way they are absorbed in the body. How is each absorbed?

• Fat-soluble vitamins are absorbed along with dietary fat. They are then packaged into the chylomicrons along with fatty acids to be transported in the lymphatic system to the liver. There if a meal has very low fat content, absorption of fat-soluble vitamins will be impaired.

• Water-soluble vitamins are absorbed in the small intestine and transported to the liver through blood vessels (hepatic portal system).