Chapter 8: Vitamins

What increases risk for thiamin deficiency

alcohol abuse

a person with beriberi often develops

an enlarged heart and sometimes severe edema

Why are thiamin's coenzyme reactions paricularly important in the body's ATP producing energy pathways

because they breakdown carbohydrates and certain amino acids

What factors affect our ability to absorb UVB rays and synthesize vitamin D?

dark skin pigmentation, geographic latitude, time of say, season of the year, weather conditions, and amount of body surface covered with clothing or sunscreen

In thiamin's coenzyme form,

participates in reactions in which carbon dioxide (CO2) is released.

Food enrichment was initiated by federal legislation in the 1930s to help combat nutrient deficiencies such as

pellegra (niacin deficiency) and iron-deficiency anemia

Vitamin E is only synthesized in

plants, so plant products, especially oils, are the best sources

After being ingested, the B (water soluble vitamins) do what

they are first broken down from their active coenzyme forms into free vitamins in the stomach and small intestine

What four B vitamins counteract the previously mentioned losses

thiamin, riboflavin, niacin and folic acid

Most adults in North American have liver reserves of vitamin a

3-5 times higher than needed for good health, therefore vitamin A supplements by most people is unecessary

How does alcohol abuse increase risk for thiamin deficiency

Absorption and use of thiamin are profoundly diminished and excretion is increased by consumption of alcohol. The low-quality diet that often accompanies severe alcoholism makes matters worse.

Good sources of Biotin

Foods rich in protein, such as egg yolks, peanuts, and cheese, are good sources of biotin (Fig. 8-26). The biotin content of food is typically not measured and therefore often not available in food composition tables or nutrient databases.

where can vitamin d be synthesized on sunny days be stored for a "rainy day"

in the adipose cells and liver

What are good sources of vitamin E

nuts and seeds

In the NA Diet, nearly 2/3 of vitamin E is supplied by

salad oils, margarines, spreads (low-fat margarine), and shortening

The UL is based on

the risk of overabsorption of calcium and eventual calcium deposits in the kidneys and other organs

People with pernicious anemia usually do not lack

vitamin B-12 in their diets

Although there are currently no specific dietary recommendations for the amount of phytochemicals that should be consumed, what do we know?

They have protective functions with minimal side effects when consumed naturally in a variety of foods.

the beriberi associated with alcoholism is also called

Wernicke-Korsakoff syndrome

The diseases that people with osteomalacia usually have affect both vitamin D activation and calcium absorption, leading to

a decrease in bone mineral density

Instead of lacking vitamin B-12 in their diets, people with pernicious anemia suffer from

an autoimmune disease that destroys the stomach cells that produce gastric acid and intrinsic factor.

at birth, a newborn has a sterile git, which means

an intestinal tract with an insufficient amount of bacteria

How is vitamin D considered one of the most potent regulators of cell growth

because they are capable of influencing normal developement of some cells (skin, colon, prostate, and breast) in turn reducing cancer risk in these sites

Vitamin K is important for two things:

blood clotting and bone health

Due to the role of vitamin D in calcium absorption, excretion, and release of calcium from bone, supplementation with high doses of vitamin D can cause

calcium levels in the blood to increase above the normal range

Without sufficient vitamin A, the cells in the eye...

cannot quicly readjust to dim light, causing night blindness

What chronic diseases does vitamin D have a role of prevention in

cardiovascular disease, diabetes, and hypertension

Vitamin A and carotenoids play roles in

cellular differentiation and embryonic development

What does vitamin A support the activity of

certain immune system cells, specifically, the T-lymphocytes, or T-cells

The symptoms of pellegra, which is a niacin deficiency that means rough or painful skin are

dementia A general loss or decrease in mental function. diarrhea, and dermatitis (especially on areas of skin exposed to the sun). Left untreated, death often results.

Vitamin B-6 deficiency also results in widespread symptoms, including

depression, vomiting, skin disorders, irritation of the nerves, anemia, and impaired immune response.

In its coenzyme form, biotin aids in

dozens of chemical reactions. Biotin assists in the addition of CO2 to other compounds, a reaction critical in synthesizing glucose and fatty acids, as well as breaking down certain amino acids.

The most important function of vitamin B-12 is

folate metabolism

Besides calcium regulation and bone health, vitamin D is also involved in

gene expression and cell growth

how is the nutritional health of most North Americans with regard to B vitamins? In addition, what type of food is fortified with B vitamins?

good, many common foods such as ready to eat breakfast cereals

vitamin b-6 also plays a role in

homocysteine metabolism

where is preformed vitamin A found

in liver, fish oils, fortified milk, butter, yogurt, and eggs, along with margarine and spreads

Osteomalacia can result from

inadequate calcium intake, inefficient calcium absorption in the intestine, or poor conservation of calcium by the kidneys

Because of their role in energy metabolism, needs for many B vitamins

increase somewhat as energy expenditure increases

What is a suggested way to prevent several chronic diseases that are linked to oxidative damage?

increasing vitamin E intake

The epithelial tissues serve as important barriers to

infection

Vitamin A deficient humans have an increased

infection rate, but when they are supplemented with vitamin A, the immune system improves

Vitamin B-12 is required to convert folate coenzymes

into the active forms needed for metabolic reactions, such as DNA synthesis. Without vitamin B-12, reactions that require certain active forms of folate do not take place in the cell.

How is vitamin D involved in cell growth

it binds to and subsequently affects cells of the immune system, brain and nervous system, parathyroid gland, pancreas, skin, muscles, and reproductive organs.

Calcium deposits in organs can cause

metabolic disturbances and cell death

Another vital function of vitamin B-12 is maintaining the

myelin sheath that insulates neurons. Initial neurological symptoms of vitamin B-12 deficiencies include irregular muscular actions and impaired reflexes. Eventual destruction of the myelin sheath causes paralysis and, perhaps, even death. In the past, vitamin B-12 deficiencies eventually led to death, mainly due to the destruction of nerves.

When the chyme reaches the duodenium,

pancreatic enzymes release vitamin B-12 from R-proteins. The free vitamin B-12 then combines with intrinsic factor. The vitamin B-12-intrinsic factor complex travels the length of the small intestine to the ileum, where vitamin B-12 is finally absorbed.

What type of people does osteomalacia most commonly occur in

people with kidney, stomach, gallbladder, or intestinal disease (especially when most of the intestine has been removed) and in people with cirrhosis of the liver.

major sources of thiamin include

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

Major sources of riboflavin are

ready-to-eat breakfast cereals, milk and milk products, enriched grains, meat, and eggs. Vegetables such as asparagus, broccoli, and various greens (e.g., spinach) are also good sources.

examples of preformed vitamin A

retinol, retinal, and retinoic acid

vitamin D deficiency can occur at any time, but when it occurs during infancy and early childhood, it is known as

rickets

How many IU of vitamin D do we synthesize in ten to fifteen mins?

roughly 3000 IU

Rich sources of pantothenic acid are

sunflower seeds, mushrooms, peanuts, and eggs. Other rich sources are meat, milk, and many vegetables.

Best source of vitamin D

sunlight

A key role of the folate coenzyme is to

supply or accept single carbon compounds. In this role, folate coenzymes help form DNA and metabolize amino acids and their derivatives, such as homocysteine. Folate works along with vitamins B-6 and B-12 to metabolize homocysteine.

To counteract the loss of nutrients when grains are refined, the US

takes bread and cereal products made from milled grains and enriches them with four B vitamins and with mineral iron

The toxic by-products of cigarette smoke and the oxidizing agents found in tobacco products increase the need for

the antioxidant action of vitamin C

Because of the role of vitamin B-6 in hemoglobin synthesis, a deficiency in vitamin B-6 would affect multiple body systems, including

the cardiovascular, immune, and nervous systems, as well as overall energy metabolism.

while food is in the stomach, the stomach cells release a protein like compound called

the intinsic factor

What three metabolic pathways require input from B vitamins?

those used for carbs, fats, and amino acids

What depends upon vitamin k for their function in bone mineralization?

three calcium binding proteins

One of thiamin's primary functions is

to release energy from carbohydrate

major sources of niacin are

tuna, poultry, peanuts, fish, ready-to-eat cereals, beef, and asparagus. Coffee and tea also contribute some niacin to the diet

Since infants have no vitamin K when born which allows for effective blood clotting if the infant needs surgery or is injured,

vitamin K is routinely administered by injection shortly after birth

Toxicity symptoms also include

weakness, loss of appetite, diarrhea, vomiting, mental confusion, and increased urine output

the symptoms of thiamin deficiency disease beriberi include

weakness, loss of appetite, irritability, nervous tingling throughout the body, poor arm and leg coordination, and deep muscle pain in the calves

what is a good example of grain product besides fortified breakfast cereals that contain vitamin E?

wheat germ