Ch. 8 - Vitamins

What is *beta-carotene*?

- An antioxidant that helps prevent macular degeneration - No Tolerable Upper Limit; if eaten in excess can turn skin yellow or orange

What forms do vitamin A come in?

- Beta-carotene (provitamin) - Retinol (active form, stored in the liver)

What is the recommended vitamin A intake for men and women?

- DRI men: 900 micrograms per day - DRI women: 700 micrograms per day

Which B vitamins participate in homocysteine metabolism?

- Folate - B-6 - B-12

What are the functions of vitamin A in the body?

- Gene expression, regulation - Vision - Skin health (epithelial cell differentiation) - Immune system - Bone growth - Reproduction

What factors can damage or reduce vitamins in food?

- Light - Oxygen - Heat

What are the toxicity symptoms of vitamin A (preformed retinol only)?

- Nausea, vomiting, diarrhea - Joint pain, loss of coordination - Rashes - Hair loss - Stunted growth - Liver damage - Enlarged spleen - Weak bones

What are the deficiency symptoms of vitamin A?

- Night blindness (reversible) - Xerosis, Xeropthalmia (scarring of cornea irreversible) - Keratinization of epithelial cells - Growth/reproductive failure - Impaired immune system

What are the physical problems that may result from *folate deficiency*?

- Spina bifida - Macrocytic anemia

What steps can be taken to reduce nutrient losses when storing fruits and vegetables?

- Store fresh produce in closed containers in the refrigerator. - Freeze fresh produce if it will not be eaten within a few days. - Delay washing and peeling fresh produce until just before eating.

What vitamins have antioxidant functions?

- Vitamin A - Vitamin C - Vitamin E - Beta-carotene - Lycopene - Lutein - Selenium - Manganese - Zeaxanthin

What is the tolerable upper intake level for vitamin A (retinol only)?

3,000 micrograms (10,000 IU)

Vitamin ___ is important for vision.

A

What is *homocysteine*?

An amino acid produced when proteins are broken down.

What are the deficiency symptoms of *vitamin B-12*?

Anemia characterized by many large red blood cells in the bloodstream despite adequate folate intake; can lead to nerve degeneration' paralysis, and death.

Why are older people at increased risk for vitamin B-12 deficiency compared to younger people?

As you age your stomach produces less acid, which limits cleavage of vitamin B-12 from food. In addition, decreased production of intrinsic factor by the stomach limits vitamin B-12 absorption.

What is vitamin K's role in the body?

Assists with blood clotting

What is a good source of *vitamin C*?

Citrus fruits

Vitamin ___ is a hormone.

D

What is a good source of *vitamin K*?

Dark leafy greens

Vitamin ___ is an antioxidant that protects cell membranes.

E

True or False: Overall, food processing increases the vitamin content of fruits and vegetables.

False

What vitamin is most likely to be supplemented to prevent neural tube defects during pregnancy?

Folic acid

What is a good source of *vitamin D*?

Fortified milk

What is vitamin B-6's role in the body?

Important for hemoglobin synthesis

What is vitamin A's role in the body?

Important for vision

What is vitamin D's role in the body?

Increases calcium and phosphorus deposition in bones

What are the deficiency symptoms of *riboflavin* (vitamin B-2)?

Inflammation of the mouth and tongue, inflamed skin, and cracking of the tissue at the corners of the mouth.

What are the deficiency symptoms of *niacin* (vitamin B-3)?

Initial symptoms include poor appetite, weakness, and weight loss; advanced symptoms include dementia, diarrhea, and dermatitis.

Vitamin ___ activates blood clotting factors.

K

What are the food sources of retinol?

Liver, fish oil, eggs, fortified milk, butter, fortified cereals

What is vitamin E's role in the body?

Neutralizes free radicals in cell membranes

What vitamin is most likely to be supplemented to boost HDL levels in an individual with a history of cardiovascular disease?

Niacin

What is a good source of *vitamin E*?

Plant oils

What is vitamin C's role in the body?

Promotes collagen synthesis

What cooking method is best for preserving vitamin content of fresh vegetables?

Steaming or stir-frying

Why is it advisable to consume vitamins in the form of whole foods every day?

The body has limited storage capacity for many vitamins, so they should be consumed daily in the diet.

What are folate functions in metabolic reactions?

They involve the transfer of single carbon groups, including synthesis of DNA, amino acids, and neurotransmitters.

True or False: Locally grown produce that is in season is likely to have higher nutrient content than imported produce.

True

What are the food sources of beta-carotene?

Vegetables and fruits (orange colored, dark green)

What are the fat soluble vitamins?

Vitamin A, D, E and K

What are the water soluble vitamins?

Vitamin B and C

What vitamin is most likely to be supplemented to prevent anemia and neurological symptoms while following a strict vegan diet?

Vitamin B-12

What vitamin is most likely to be supplemented to alleviate nausea during the first trimester of pregnancy?

Vitamin B-6

What vitamin is most likely to be supplemented to prevent further bone malformations in a child with outwardly bowed legs indicative of rickets?

Vitamin D

What vitamin is most likely to be supplemented to assist blood clotting in a newborn baby whose intestinal tract in not yet populated with vitamin-producing bacteria?

Vitamin K

What are the deficiency symptoms of *thiamin* (vitamin B-1)?

Weakness and loss of appetite, nervous tingling throughout the body, poor coordination, and severe edema.

What are the deficiency symptoms of *vitamin C* (ascorbic acid)?

Weakness, slow wound healing, bone pain, bleeding gums, and pinpoint hemorrhages on the skin.

Elevated homocysteine levels are linked to...

cardiovascular disease and dementia.

Vitamin A is _____ soluble.

fat

One symptom of B vitamin deficiencies is depression, due to the role of several B vitamins in ______ synthesis.

neurotransmitter