4: micronutrients - m + vitamins

vitamin D and niacin

The human body cannot make its own vitamins except _______ and ____ which are produced in the body.

1. Vitamin A (Retinol)

vision cycle Epithelial tissue Growth and bone development Reproduction -

Vitamin Malnutrition

- The prefix "mal" meaning bad denotes that too much or too little vitamin is not good for the health

ADEK

A. Fat-soluble Vitamins

Skin lesion

Characterized as "food skin" clinically known as phrynoderma, skin lesion appears as dry and rough skin with popular eruptions occurring around the hair follicles. The sites of dermal changes are usually in the thighs, abdomen, upper arm, and back

loss of appetite

Shortage of vitamins particularly A, B, and C may result in _____.

Vitamin-like Compounds

Some substances have physiological roles like vitamins but they are present in larger amounts and are partially synthesized in the body. These substances include inositol, choline, lipoic acid, and ubiquinone

Precursors or Provitamins Preformed Vitamins Avitaminosis Hypervitaminosis Vitamin Malnutrition Vitamin-like Compounds Antivitamins or Vitamin Antagonists

Terms Associated with Vitamins

Antivitamins or Vitamin Antagonists

These are substances that interfere with the normal functioning of a vitamin. They need to be similar in chemical composition as the vitamin they "antagonize." Examples are dicumerol against vitamin K, avidin against biotin, and thiaminase against thiamine or vitamin B1

Vitamins

They are also crucial in the growth, repair, and healthy functioning of body tissues.

vitamins

They are the last group of organic compounds which were discovered to be vital to life maintenance and growth.

Eye lesionq

This condition is the most critical in avitaminosis A. The cornea of the eye is affected early, and the lacrimal gland fails to function, followed by keratinization and rupture of the corneal tissues Infection sets in

accessory food factors

Vitamins are formally called "_______" because their presence in minute quantities is easily overlooked

1. Vitamin A (Retinol)

a.1 Preformed vitamin A - animal sources a.2 Provitamin A - precursor carotene; pigment found in green and yellow plants; body converts into vitamin A

Vitamins

are a group of unrelated organic compounds found in food which are needed only in minute quantities in the diet but essential for specific metabolic reactions within the cell and necessary for normal growth and maintenance of health

Vitamins

do not give energy to the body. They merely help convert food into energy through many biochemical reactions

1. Fat-soluble vitamins generally have precursors or provitamins. 2. Because they can be stored in the body, deficiencies are slow to develop. 3. They are not absolutely needed daily from food sources. 4. They are generally stable, especially in ordinary cooking methods.

fat-soluble vitamins differ from water-soluble vitamins based on the following factual criteria

Vitamin A (Retinol) Reproduction

intake must be increased to assure normal reproduction and lactation. Although not yet clear, the role of vitamin A in reproduction may be in steroid hormone synthesis or in cellular differentiation

1. Vitamin A (Retinol) visison cylce

is a necessary component of visual purple (rhodopsin), light-sensitive pigment in the retina enabling it to make adjustments to light and darkness. Retinal is a prosthetic group of photosensitive pigments of both rods (rhodopsin) and cones (iodopsin).

1. Vitamin A (Retinol) Growth and bone development

is also necessary for the growth and development of skeletal and soft tissues through its effect upon protein synthesis and differentiation of bone cells. It also affects tooth formation in the early life of animals forming epithelial cells. Excessive vitamin A, however, causes complete disintegration of the bone matrix

1. Vitamin A (Retinol) epithelial tissue

plays a vital role in the proper synthesis and maintenance of epithelial tissue, hence the integrity of skin and internal mucosa and growth and formation of tooth buds. When vitamin A is lacking, keratinization

1. They must be supplied every day in the diet. 2. They do not have precursors. 3. They are not stored significantly in the body and any excess is excreted in the urine. 4. Deficiency symptoms develop relatively fast. 5. Being water-soluble, they are most likely to be destroyed in ordinary cooking.

water-soluble vitamins have the following general characteristics:

1. Vitamin A (Retinol)

is rather stable to light and heat, but prolonged heating in contact with air destroys it. It is easily destroyed by oxidation and ultraviolet light. A cool atmosphere and refrigeration tend to preserve this vitamin. Vitamin E may be used with vitamin A to preserve the latter

1. The fat-soluble vitamins A, D, E, and K in association with lipids are found in foods. 2. The water-soluble vitamins are B complex and vitamin C

Classification of Vitamins on the Basis of Solubility

Casimir Funk 1912 beriberi

The word vitamin was coined by __________ in ________ when he was searching for a constituent in rice bran which could cure ____. The missing substance he called vitamine comes from vita meaning necessary for life and amine denoting that the anti-beriberi factor contained nitrogen. He hypothesized that nutritional deficiencies which were observed in the past such as scurvy, pellagra, and rickets, were due to the lack of "vitamine." Researchers later showed that not all these dietary factors contained nitrogen, so the final letter "e" was dropped, hence the word "vitamin"

Precursors or Provitamins

These are compounds that can be changed to active vitamins. For example, carotenes and cryptoxanthin are precursors of vitamin A. Ergosterol when radiated becomes vitamin D.

Preformed Vitamins

These are naturally occurring vitamins that are in inactive form and ready for biological use

Hypervitaminosis

This is sometimes referred to as "vitamin toxicity." a result of excessive accumulation of a vitamin in the body

Avitaminosis

This refers to a condition resulting from lack of a vitamin. In the later stage of this condition when more defined signs and symptoms occur, a nutritional deficiency disease is recognizable

1. Vitamin A (Retinol)

b.1 Absorption aided by bile salts, pancreatic lipase, and dietary fat b.2 Carotene converted into vitamin À in intestinal wall b.3 Absorbed through lymphatic system and portal blood to liver (same route as fat) b.4 Large storage capacity in liver, hence potential toxicity levels with large intakes

Poor adaptation or night blindness Eye lesion Retarded growth Lower resistance to infection Faulty skeletal and dental development Keratinization of epithelial linings Disturbances in genitourinary tracts Skin lesion

deficiency of vitamin A

Latin vita life nitrogen compound

word vitamin comes from the ____ word ___ meaning ___ and the suffix amine, which is a ______. It was discovered later that not all vitamins contain nitrogen; nevertheless, "vitamin" has been used pervasively and has become a common word