HUN 1201- Chapter 8 Vitamins

What are two compounds that niacin functions in the body as?

1. Nicotinic acids 2. Nicotinamide

Where is Vitamin A stored?

90% in liver; 10% in adipose tissue, kidneys and lungs

Vitamin K (Quinone)

A family of compounds found in plants, plant oils, fish oils and animal products and in intestinal bacteria; *it is a cofactor in chemical reactions that add CO2 molecules to various proteins, thus enabling these proteins to bind calcium.*

Niacin Toxicity

(Above 100 mg per day) Headache, itching, increased blood flow to the skin because of blood vessel dilation or flushing in various parts of the body. In the long run, the GI tract and liver can be damaged. Megadoses require medical supervision

Functions of Vitamin K

*1)Clotting-* Cofactor in chemical reactions that add CO2 molecules to various proteins, thus enabling these proteins to bind calcium. The calcium binding ability that is given to seven proteins lead to the coversion of fibrinogen into insoluble fibrin which is the clot. *2) Maintaining bone health-* three calcium-binding proteins in the bone depend upon vitamin K for their function in bone mineralization

Ariboflavinosis

*Riboflavin deficiency*; resulting in the irritation of the skin, mouth and throat, dermatitis, cracking of tissue around the corners of the mouth (cheilosis), various eye disorders, sensitivity to the sun, and confusion; usually accompanied by low overall intakes of calories and proteins

Sources of Niacin (B3)

-Can be synthesized from the amino acid tryptophan -Lean meats, poultry, fish -Peanuts and peanut butter -Brewer's yeast -Fortified breads and cereals -Legumes -Seeds and nuts

The B vitamins functions as....

...coenzymes, small molecules that interact with enzymes to enable the enzymes to function

Sources of Provitamin A Cartenoids include...

...dark green and yellow orange vegetables and some fruits. (Spinach, carrots, squash, kale)

The best way to preserve vitamin content if eating it right after its harvest is not a options, is....

...freezing.

How does Vitamin D regulate calcium?

1) Influences the absorption of calcium and phosphorus from the small intestine 2)It works in combination with parathyroid hormone (PTH) and calcitonin to regulate calcium excretion via the kidney 3) IT affects the deposition and withdrawal of minerals from the bone

Dietary cartenoids do not produce toxic effects because:

1) Their rate of conversion into Vitamin a is slow and regulated 2) The efficiency of carotenoids absorption from the small intestine decreases markedly as oral intake increases

Vitamin K Deficiency Causes

1. A newborn has no bacteria in its stomach which means it does not produce enough Vitamin K for a serious injury or surgery 2. Extended antibiotic use that can kill bacteria that produces menaquinone 3. Fat absorption is limited

What three cartenoids can be converted into retinol? (*Provitamin A*)

1. Alpha carotene 2. Beta carotene (serves as a signif. source) 3. Beta cryptoxanthin

neural tube defect

caused by maternal folate deficiency; linked in the development of spina bifida and anencephaly

Folate is a ...

coenzyme

Anencephaly

congenital deformity in which some or all of fetal brain is missing

Megadose

Intake of a nutrient well beyond estimates of needs to prevents a deficiency or what would be found in a balanced diet; *2 to 10 times* above human needs is typically a starting point for such dosage

Where is Vitamin E stored?

It is stored in *adipose tissue* throughout the body, NOT the liver.

What is unique about Vitamin D?

It is the only nutrient that is a *hormone* (a compound manufactured by one organ or tissue in the body that enters the blood stream and has a physiological effect on another organ or tissue) and vitamin; it also can be produced in the *skin exposure to ultraviolet rays*

What is riboflavin destroyed by?

Light (That's why milk is stored in opaque container, to protect the Riboflavin)

Sources of Vitamin B

Liver, fish, eggs, yeast, dried beans, peas, and whole grains

Sources of Vitamin E

Plant oils, margarine, salad oils, shortening, fortified breakfast cereal, wheat germ, sunflower seeds

Sources of Thiamin (Vitamin B1)

Pork products, whole grains (wheat germ), ready-to-eat breakfast cereals, enriched grains and flour, green beans, milk, orange juice, organ meats, peanuts, dried beans, and seeds (*Protein and Grains*)

Cartenoids

Precursors of Vitamin A found in *plant foods*

Vitamin D RDA, DV, and UL

RDA : 15 mc DV: 10 mc UL: 100 mc

Niacin (B-3) DRIs

RDA: Men- 16 mg Women- 15 mg DV: 20 mg UL: 35 mg (nicotinic acid form found in supplements)

Vitamin E RDA, DV, UL

RDA: 15 mg DV: 30 mg UL: 1000 mg

Thiamin DRIs

RDA: Men-1.2 mg Women- 1.1 mg DV: 1.5 mg UL: none

Vitamin D Toxicity

Raises the concentration of blood calcium High amounts of blood calcium can cause kidney stones, weakness, loss of appetite, diarrhea, vomiting, mental confusion and increased urine output. *Vitamin D toxicity cannot occur from sun exposure.*

Sources of Riboflavin (B2)

Ready-to-eat breakfast cereals, milk, milk products, enriched grains, meat, eggs, asparagus, broccoli, and various greens (e.g., spinach)

Vitamin A toxicity

Reduced bone mineral density, liver abnormalities, birth defects; hypocarotenemia

Sources of Vitamin D:

Sunlight, fortified foods (milk, cereal, bread, orange juice), fish liver oils, mushrooms

Pellagra

The *niacin-deficiency disease*. Symptoms include the 4 Ds: diarrhea, dermatitis (in areas exposed to the sun), dementia (A general loss or decrease in mental function), and ultimately, death.

Beriberi

The *thiamin-deficiency disease*; characterized by weakness, loss of appetite, irritability, nervous tingling throughout the body, poor arm and leg coordination and deep muscle pains in the calves. They often develop an enlarged heart and severe edema.

Bioavailibilty

The degree to which an ingested nutrient is digested and absorbed and this is available to the body

Tissue saturation

The limited storage capacity of water-soluble vitamins in the tissues

Why would taking a mineral oil inhibit fat-soluble vitamin absorption?

The mineral oil, a fat, would absorb those vitamins. Then, the mineral oil that is not absorbed through the intestine will pass these vitamins until it reaches the feces without being absorbed.

Scurvy

The vitamin C-deficiency disease characterized by weakness, fatigue, slow wound healing, bone pain, fractures, sore and bleeding hums, diarrhea and pinpoint hemorrhages on the skin

How are water soluble vitamins absorbed?

They are first transported to the stomach and broken down into free vitamins. Then, they are absorbed in the small intestine and then transported to the liver via the hepatic portal vein to be redistributed to the tissues. Then, in cells, they are assembled back to their active coenzyme forms.

In corn, the protein bound to niacin inhibits its absorption. (True/False)

True, for that reason, diets with high amounts of corn can lead to pellagra. Soaking the corn in a alkaline solution frees the niacin.

How is vitamin D synthesized?

UVB rays of the sun convert a cholesterol precursor of Vitamin D (7-dehydrocholesterol) found in the skin into an inactive form of vitamin D3 (cholecalciferol). This compound is then activited to 25-hydroxyvitamin D3 (calcidiol) in the river and to 1, 25-dihydroxyvitamin D3 (calcitriol) in the kidney before it can function as the Vitamin D hormone

Among pregnant women, night blindness is a marker of _______________ _____ deficiency that will likely lead to pregnancy related death, malnutrition, anemia, or infant mortality.

Vitamin A

The fat-soluble vitamins (A, D, E and K) are absorbed with ____________ ________. Fat-soluble vitamins are stored mostly in the ___________ and _________ ___________.

dietary fat; liver; fatty tissues

Folate sources

green leafy vegetables, orange juice, organ meats, dried beans, fortified breakfast items (cereal, milk, bread)

Folate deficiency can result in

megaloblast, megaloblastic anemia, neural tube defects, spina bifida, and anencephaly

Key role of folate

supply or accept single carbon compunds

Folic acid

the synthetic form of folate, a substance required for hemoglobin and amino-acid synthesis, cellular reproduction, and prevention of neural tube defects in utero

Hyperkeratosis

A *Vitamin A deficiency* where skin cells produce too much keratin and causes skin to be hard and dry

Rickets

A disease characterized by *poor mineralization* of newly synthesized *bones* because of low calcium content. Arising in *infants and children,* it is caused by *insufficient vitamin D*; those afflicated have bowed legs, thick wrists and ankles, curvature of spine and pigeon chest

Vitamin E

A family of four tocopherols and four tocotrienols called alpha, beta, gamma and delta. Tocopherols have a saturated side chain, whereas tocotrienols have an unsaturated side chain. Alpha tocopherol is the most biologically active and the most potent.

Riboflavin (Vitamin B2) DRIs

RDA: Men- 1.3mg Women-1.1 mg DV: 1.7mg UL: none

Choline

Related nutrient that has vitamin-like characteristics but currently not classified as one

What are the B vitamins?

Thiamin (B1), Riboflavin (B2), Niacin, Pyridoxine (B6), Folate, Cobalamin (B12), Panthothenic Acid, Biotin

Spina bifida

birth defect characterized by the spinal chord or spinal fluid bulging through the back or outside of the spinal column

Vitamin E is only synthesized by

plants (especially oils).

Vitamin A is in a group of compounds known as _________.

retinoids

B vitamins include....

thiamin, riboflavin, niacin, vitamin B6, folate, vitamin B12, pantothenic acid, and biotin.

Zoochemicals

Chemicals found in animal products that have health-protective actions

Classifications for vitamins:

1. The body is unable to produce enough to maintain health 2. The absence of the compound from the diet produces deficiency that can be reversed if compound is reintroduced intime

What water soluble vitamins are not easily excreted?

B-6 and B-12

Antioxidant

A substance that slows down oxidation, foods include blueberries and green vegetables. They eliminate free radicals that can destabilize a cell membrane and cripple a cell's ability to function.

Night blindness

A vitamin A deficiency disorder that results in loss of the ability to see in dim light

Vitamin K AI, DV, UL

AI: Men- 120mg Women- 90mg DV: 80mg UL: none

Osteomalacia

Adult form of rickets. The bones have low mineral density and subsequently are at risk for fracture. It

How are B-vitamins absorbed?

After being ingested, the B vitamins are first broken down from their active coenzyme forms into free vitamins the stomach and small intestine. The vitamins are then absorbed, primarily in the small intestine. Typically, about 50% to 90% of the B vitamins in the diet are absorbed, which means that they have relatively high bioavailibility. Once inside cells, the active coenzyme form themselves. Some vitamins are sold in their coenzyme forms, but these are broken down during digestion, and we activate them when needed.

What vitamins may accumulate to toxic levels?

All fat soluble vitamins EXCEPT Vitamin K, Vitamin B-6, Vitamin B-12

Vitamin

An essential organic compound needed in small amounts in the diet to help regulate and support chemical reactions and processes in the body

Why would a B-vitamin deficiency typically affect the brain, nervous system skin and gastrointestinal tract?

As B-vitamin is an enzyme, it is required in locations that are metabolically active like those locations

Coenzyme

Compound that activates an enzyme

What can affect our ability to synthesize vitamin D?

Dark skin pigmentation, geographic latitude, tine of day, season of the year, weather conditions, and amount of body surface covered with clothing or sunscreen

The best source of Vitamin A is supplements (True/False).

False, Vitamin A intake from foods has shown the most promise of cancer prevention and optimal health.

Choline is a vitamin. (True/False)

False, choline is a vitamin-like nutrient.

Functional foods

Foods that have health benefits beyond basic nutrition

Vitamin D2 (ergocalciferol)

Form of vitamin D found in nonanimal sources, such as in some mushrooms

Xerophthalmia

Hardening of the cornea and the drying of the surface of they eye, which can result in blindness (Extreme Vitamin A deficiency)

Vitamin E Toxicity

May interfere with blood clotting action of Vitamin K leading to a hemmorage

Vitamin A RDA

Men: 900 micrograms/day Women: 700 micrograms/day DV: 900 mg RAE UL: 3000 mg RAE

What fat soluble vitamin is easily secreted?

Vitamin K

What cells participate in the synthesis of active Vitamin D hormone?

Skin, liver and kidney cells

Vitamin K Sources

Spinach, kale, broccoli, green leafy vegetables, gut bacteria, some meats, eggs, and dairy products

Retinyl

Storage form of Vitamin where *retinol is esterified* (joined with a fatty acid)

What vitamin directly affects calcium absorption?

Vitamin D

Two types of Vitamin D:

Vitamin D2- A synthetic product derived from the irradiation of plant sterols and is used by some supplements Vitamin D3-the form synthesized in the human body (it used in supplements and fortified foods)

Fat-soluble vitamins

Vitamins that dissolve in fat and such substances as ether and benzene but not readily in water. These *vitamins are A, D, E, and K.*

Water-soluble vitamins

Vitamins that dissolve in water. Theses vitamins are the B and C vitamisn

Megaloblast

a large, immature red blood cell caused by the lack of DNA synthesis and inability for the red blood cell to form two nuclei and divide

Vitamin E Functions

1. Antioxidant- it can donate electrons or hydrogen to free radicals found in membranes, making them more stable. This is important for lung cells 2. Important for the formation of muscles and the central nervous system in early human development 3. Functions in the metabolism of iron within cells and it helps maintain nervous tissue and immune function

Functions of Vitamin D

1. Blood calcium regulation- calcitriol is used to maintian the normal ranges of calcium and phosphorus in the blood 2. Gene expression and cell growth

Thiamin (B-1) Deficiency causes

1. In poor countries, white rice are eaten rather than brown rice and white rice is a poor source of B-1 2. Alcoholism diminishes the absorption of thiamin (Wernicke-Korsakoff syndrome)

Functions of Riboflavin (Vitamin B2)

1. It's co-enzyme forms, flavin dinucleotide (FAD) and flavin mononucleotide (FMN), participate in many energy yielding metabolic pathways, such as the breakdown of fatty acids. 2. Some metabolism of vitamins, and minerals also requires riboflavin 3. Indirectly, Riboflavin also has an antioxidant role in the body through its support of the enzyme glutathione peroxidase

Niacin Functions (B-3)

1. It's coenzyme form, nicotinamide adenine dinucleotide (NAD) or nicotinamide adenine dinucleotide phosphate (NADP), is used ATP is generated by burning carbohydrates and fats 2. Anabolic (make bigger things with smaller things) often used a niacin coenzyme. Especially for fatty-acid synthesis

Preservation Methods:

1. Keep fruits and vegetables cool 2. Refrigerate fruits and vegetables (excepts bananas, onions, potatoes, and tomatoes) in the vegetables drawer 3. Alter foods minimally (ex. cutting, peeling) 4. Microwave, steam or stir-fry vegetables 5. Avoid adding fats if you will discard them 6. Do not add baking soda 7. Store canned and frozen fruits and vegetables carefully

What are the functions of Vitamin A?

1. Maintaining the health of epithelial cells (required for immature epithelial cells to develop into mature, functional epithelial cells) 2. Support the activity of T-lymphocytes (T-cells) which are immune cells used to fight infection 3. Participates in the processes of growth, development, and reproduction. It binds to receptors on DNA to increase the synthesis of a variety of proteins. 4. Functions in the differentiation and maturation of cells 5. Assists with breakdown and formation of healthy bone tissue 6. Aids in sperm production and in a normal reproduction cycle for women

Vitamin A deficiencies:

1. Night Blindness 2. Hyperkeratosis 3. Xerophthalmia

Thiamin (Vitamin B1) Function

1. Part of Coenzyme TPP which participates in reactions in which CO2 is released 2. Helps release energy from carbohydrates 3. Participates in conversion of pyruvate to Acetyl CoA 4. Functions in chemical reactions that make RNA, DNA and neurotransmitters

Three forms of Vitamin K:

1. Phylloquinone (most abundant form, synthesized by green plants) 2. Menaquinone (Synthesized by gut bacteria) 3. Menadione (Synthetic form found in supplements, it is twice as biologically available as the other two)

What groups of people are susceptible to Vitamin E deficiency?

1. Preterm babies as Vitamin E was not transferred to them from their mothers 2. Smokers, smoking destroys Vitamin E in the lungs 3.Low fat diets 4. Fat-malabsorption disorders

What are the three active forms of Vitamin A? (only exist in Animal Products)

1. Retinol 2. Retinal 3. retinoic acid (Preformed vitamin A)

megaloblastic anemia

anemia characterized by the presence of large red blood cells; macrocytic or large-cell anemia; the body's capacity to carry oxygen decreases