7A

FN 225: Nutrition
Rathakette, Ph.D.
Health Professions Division
Lane Community College
Eugene, Oregon

FORUM for Week 7: see wk 7 forum

LECTURE 7A: Vitamins & Minerals- part 1

Use this information to start filling out the lecture outline for chapter 7 & 8.

A vitamin is defined as an essential non-caloric organic nutrient needed in tiny amounts in the diet. As you learned in Week 1, vitamins are organic and DO have calories, but they don't have calories for us because we don't make the enzymes we'd need to break vitamins apart to release the energy. So that's what I mean by non-caloric. There would be very little energy there for us anyway- GRAMS of starch, sugar and fat give us a lot more energy than MILLIGRAMS of vitamin C. And we need that vitamin C for important functions in the body.

A mineral is defined as an essential non-caloric inorganic nutrient also needed in tiny amounts in the diet.

Vitamins can be divided into 2 categories:

Fat-soluble vitamins are absorbed with fats from food into lymph then travel hooked to protein carriers (“boats”) and they are stored in fatty tissues. As you can see with the image below, fat-soluble vitamins include vitamin E, vitamin A and its precursor beta-carotene, vitamin K and vitamin D.

Beta-carotene is fat-soluble, but most foods with beta-carotene, like carrots, are low in fat. It takes very little fat for that beta-carotene (a pigment) to be soluble.

I got some carrots I was grating in my lap and didn't notice them until they'd been there for awhile. The beta-carotene pigment stained the skirt and it took several washings to remove the stain.
Water-soluble vitamins are absorbed directly into blood where they travel freely (NOT hooked to protein carriers) and are not stored in body but tissues can be “saturated”. Water-soluble vitamins include vitamin C and the 8 B-complex vitamins, including the lesser-known biotin and pantothenic acid, as well as vitamin B₆ (pyridoxine), vitamin B₁₂ (cobalamin), thiamin (vitamin B₁), folate, niacin (vitamin B₃) and riboflavin (vitamin B₂).

Minerals are absorbed directly into blood and are always water-soluble. Examples of minerals include iron, calcium, zinc, magnesium, potassium, sodium, chloride, fluoride, manganese, phosphorus and selenium.

Minerals and water-soluble vitamins are absorbed directly into blood. Fat-soluble vitamins are absorbed into the lymph.

You saw the above image earlier in the term. It shows why vitamins are organic (contain carbon to carbon bonds) and minerals are inorganic.

Looking at the Ingredient list for Honey Nut Chex cereal, which ingredients are:

Fat-soluble vitamins
Water-soluble vitamins
Minerals

Minerals are different than vitamins because they are INorganic, therefore they don't have calories. Also minerals are always absorbed directly into the blood.

Vitamin A and vitamin C are both organic. But Vitamin A is a fat-soluble vitamin so it is absorbed into the lymph, and travels with a carrier and is stored.

Vitamin C is a water-soluble vitamin so it is absorbed directly into the blood, travels without a carrier and is not stored.

Plants get vitamins by making them because they need them to function. Many of the vitamins that plants make are actually antioxidant pigments that they make to help them with photosynthesis. And each plant has its own set of pigments that it needs. A plant making orange carrots needs carotenes while a plant making cream-coloredparsnips needs flavones.

Parsnips

Antioxidants in Photosynthesis and Human Nutrition, Demmig-Adams, Barbara; Adams, III, William W. Science; 12/13/2002, p2149, 5p. The harnessing of solar energy by photosynthesis depends on a safety valve that effectively eliminates hazardous excess energy and prevents oxidative damage to the plant cells. Many of the compounds that protect plant cells also protect human cells and have a role in human nutrition.

Vitamins can be made in the body in 2 ways. One way is from precursors, which are something that can be changed into an active vitamin. For example, niacin can be made from the amino acid tryptophan.


Tryptophan (above)	Niacin

Retinol (the active form of Vitamin. A) can be made from beta-carotene in plant food.


Retinol	Beta-carotene

Vitamin D can be made when ultraviolet light in sunlight strikes cholesterol in the skin. So cholesterol, which our body can make, is a precursor for vitamin D. These children in the country of Georgia (near Russia) are making vitamin D.


Cholesterol	Vitamin D

A second way our body can make vitamins is by letting good bacteria live within us since bacteria in our intestinal tract can make vitamin K and also biotin and pantothenic acid. Do you see on the list above what kind of nutrients biotin andpantothenic acid are?

Gut Flora? Great!, Maintaining a balance of microorganisms can help strengthen your overall health, Mary Carmichael, NEWSWEEK, Jan 23, 2006.

So now we're ready to move on to THE NUTRI-CHARTS in the lecture outline.

These charts take sort of a "Three Bears" approach to vitamins and minerals as I have always loved their story. Of the three bowls of porridge Goldilocks came upon, one was too hot, one was too cold and one was just right.

So we'll look at what happens when there's too much of a nutrient, too little of a nutrient and just the right amount of a nutrient.

NUTRI-CHART 1 lists the Nutrients Involved that can be ANTIOXIDANTS.

Antioxidants protect cell substances from damage by oxygen.

Oxygen (O₂) can combine with substances, forming free radicals (unpaired electrons), which damage cell substances.

Remember when you saw the little animated "movie" about covalent bonding earlier in the term? Unpaired electrons are "anxious". They go hunting for electrons to complete their outer shell. Unpaired electrons can grab from where they shouldn't, which can damage cells.

Antioxidants seem to be able to "scavenge & quench" free radicals & may offer some protection against cancer and effects of aging. Studies showing benefits of antioxidants have been done on antioxidants in foods, not antioxidants in supplements.

Take a look at how these charts are organized. The column on the left shows the nutrient.

Then the next column describes a little of what happens in the body when there'sTOO MUCH of that nutrient in the body.

The next column describes a little of what happens in the body when there's TOO LITTLE of that nutrient in the body.

The next column describes a little of what happens in the body when there's JUST the RIGHT amount of that nutrient in the body

Beta-carotene is changed slowly in the body to retinol, so TOO MUCH beta-caroteneis not toxic. Sometimes babies get very enthusiastic about carrots and squash and they may get excess carotene, but it doesn't have toxic effects. Their skin may turn slightly orange, but it isn't dangerous.

TOO LITTLE beta-carotene in the diet/body may elevate cancer risk.

JUST the RIGHT amount of beta-carotene can be changed in the body to retinol and then it can perform the functions of vitamin A.

Beta-carotene has functions as an antioxidant in the body that retinol cannot accomplish.

Moving on to vitamin E, TOO MUCH vitamin E can increase the effects of (interfere with) anticoagulant medication, including aspirin, risking uncontrolled bleeding.

Since vitamin E is transferred from the mother to the fetus late in a pregnancy, premature infants can be born with TOO LITTLE vitamin E. Without vitamin E's antioxidation, some blood cells rupture when oxidation destroys the cell's membrane.

JUST the RIGHT amount of vitamin E is an antioxidant for cell's lipids and proteins, especially those in the lungs and red blood cells because lungs & RBCs have high oxygen concentrations.

TOO MUCH vitamin C in the body can interfere with medical tests.

TOO LITTLE vitamin C in the body can suppress the immune system.

JUST RIGHT amounts of vitamin C in the body means the vitamin C can be an antioxidant and protect cell substances by becoming oxidized itself.

TOO MUCH selenium in the body can lead to nausea and liver damage.

TOO LITTLE selenium in the body can cause an uncommon form of heart disease.

JUST RIGHT amounts of selenium in the body means the selenium can play an antioxidant role by assisting vitamin E.

NUTRI-CHART 2 lists the Nutrients Involved in CERTAIN SPECIALIZED CELLS/TISSUES

Let's do the JUST RIGHT part of vitamin A first.

Vitamin A is needed for the production of epithelial tissue, which is both your inner and your outer skin. Examples of "inner skin" would be the lining of your lungs and intestinal tract. Epithelial tissue is also on the outside of the cornea.
Vitamin A also functions in the retina of the eye to help see in dim light.

With there is TOO LITTLE vitamin A in the body, the cells make a dry, hard protein called keratin (NOT the same thing as carotene, even though those words sound a lot alike).

A person can become blind when keratin builds up in the cornea, shown below in the Bitot's spots. A person is more vulnerable to lung infections when deficient in vitamin A because keratin builds up preventing the lungs from expelling harmful substances.

And a person without enough vitamin A can become night blind because retinol is needed for the eye to see in dim light. (There are MANY other reasons a person might be night blind besides vitamin A deficiency.)

TOO MUCH vitamin A in the body is very toxic.

JUST RIGHT amounts of vitamin C in the body helps you make collagen, the main protein that makes up connective tissue. Connective tissue has structural and supportive functions which are indispensable to blood vessels and all tissues within the body. This is one reason vitamin C can help you heal.

TOO LITTLE vitamin C in the body can lead to connective tissue problems in the gums and also the blood vessels. Two of the classic symptoms of scurvy (vitamin C deficiency) are a type of gum disease and parafollicular petechiae (pinpoint hemmorhages underneath the skin).

JUST RIGHT amounts of Vitamin D in the body affects how cells grow, proliferate & specialize. Can help keep cells from becoming malignant or have autoimmune responses & when do go bad, perhaps causes them to self-destruct.

Vitamin D may help battle breast cancer, By Marilynn Marchione, The Associated Press, inThe Eugene Register-Guard, :May 16, 2008

Part of what this article says is:

"The skin makes vitamin D from ultraviolet light. Too much sunlight can raise the risk of skin cancer, but small amounts — 15 minutes or so a few times a week without sunscreen — may be beneficial, many doctors believe.

"While the vitamin is found in certain foods and supplements, most don’t contain the best form, D-3, and have only a modest effect on blood levels of the nutrient."

Vitamin D is found in many fortified foods, such as Wheat Chex cereal. But if it only lists Vitamin D as an ingredient, it is probably NOT Vitamin D3.

TOO LITTLE vitamin D in the body may increase risk of a variety of diseases.

TOO MUCH vitamin D in the body can lead to calcification of soft tissues like the heart, blood vessels, lungs and kidneys.

Lately there has been a lot of attention and propaganda circulating around Vitamin D and it has been portrayed as the miracle Vitamin that may help fight many diseases beyond bone health. To help clarify a lot of conflicting messages that have been circulating about Vitamin D, the Institute of Medicine (IOM) updated the nutrient reference values (DRIs) for both calcium and Vitamin D. The IOM found evidence supporting a role of vitamin D and calcium in bone health, but not in other health conditions. They also challenged the idea of "more is better," and indicate that too much of these nutrients may be harmful.

Like other vitamins, whole foods is the best way to get Vitamin D. It is not very prevalent in foods, but luckily we also synthesize it from the sunshine. However, keep in mind most of the United States cannot synthesize Vitamin D November through February, making food choices even more important.

Food Sources of Vitamin D

Note: Rice and soy milk are fortified to the same levels of milk, 100 IU per cup.

Looking at the above food sources do you think you get enough Vitamin D from foods? If not, what kind of dietary changes could you make to increase your food intake of Vitamin D?

Before continuing with the remainder of Lecture 7A, watch the video below.

Video Clip: Supplies The Most Nutrients
approximately 10 minutes

Now continue below with the remainder of Lecture 7A.

NUTRI-CHART 3 lists the Nutrients Involved in ENERGY METABOLISM

There are 5 B-complex vitamins involved in energy metabolism. These are thiamin, riboflavin, niacin, pantothenic acid and biotin. Return to page 51 in your packet, where by now you should have filled in most of the blank lines.

The 5 B-complex vitamins function as part of coenzymes for cellular respiration. This means that they help the enzymes bring about the reactions that release the energy from glucose (or from fat or protein).

Notice what page 51 says at the bottom right about Ch. 7, and fill in the blanks.

What are NAD and TPP?

NAD and TPP are coenzymes containing B-vitamins. NAD stands for(niacin adenine dinucleotide, so the B-vitamin that coenzyme contains is niacin. TPP stands for thiamin pyrophosphate so the B-vitamin it contains is thiamin.

Without any of those 5 B-complex vitamins, cellular respiration couldn't happen in the body. Fatigue, and eventually death, would be the result. It would be like having no way to strike a match for (or otherwise start) a fire. You could have a large woodpile, but you couldn't get heat from that wood.

In addition to those 5 B-complex vitamins, 1 other vitamin is especially important for energy metabolism to happen and that is vitamin C. What vitamin C helps produce is thyroxin, a hormone that helps regulate the basal metabolic rate. Someone with a low BMR would be sort of like a really wimpy fire that burned slowly.

Iodine (I), chromium (Ch), manganese (Mn) and phosphorus (P) are minerals that are important for the reactions of cellular respiration to happen.

The map below shows "goiter belts", areas of the world where, for some reason, iodine has been scrubbed from the soil, perhaps because of volcanic or glacier activity.

As part of cytochromes, iron (Fe) is a coenzyme involved in energy metabolism.

Above is the structure of a cytochrome. Can you see iron?

NUTRI-CHART 4 lists the Nutrients Involved in BLOOD HEALTH

Some of the MINERALS involved in blood health include iron (Fe.... that stands for ferrous), zinc (Zn) and copper (Cu.... that stands for cupric).

Iron in food can be found in both foods of plant origin and foods of animal origin. The iron in foods of animal origin is mostly in hemoglobin and it is called "heme iron". Heme iron is better absorbed than the non-heme iron foods of plant origin.

One of the most common causes of childhood poisoning is from the ingestion of way-too-many multivitamin/mineral supplements at one time.

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Parents may be tempted to encourage children to "take their vitamins" by comparing them to candy. Children then may have the idea that they are as safe as candy, which they are not.

A child who swallows too many of them may need to have their stomach pumped because they can damage their heart.

Too much iron from supplements can also decrease the body's ability to absorb copper.
Zinc. Too much iron from supplements can also decrease the body's ability to absorb copper.
Copper. I won't say anything else besides what's in the NUTRI-CHART.

Some of the VITAMINS involved in blood health include folate, vitamins B₁₂ and B₆and also vitamins C and K.

TOO MUCH folate may accelerate growth of cancer cells but TOO LITTLE folateduring pregnancy can lead to neural tube defects in the newborn, like spina bifida (Latin for "split spine"). Although surgery can improve the situation, some aspects of the condition is permanent.

Absorbing vitamin B₁₂ requires the intrinsic factor, something that is made in the stomach. Low stomach acid, known as hypochlorhydria, interferes with the absorption of vitamin B₁₂. Aging is associated with a decrease in the normal secretion of stomach acid. As a result, some older people with normal levels of intrinsic factor and with no clear cause for malabsorption will become vitamin B₁₂-deficient.

A "megadose" level of vitamin C is often considered to be an amount that is 10 times (1000%) of the DV.

Most animals make their own vitamin C from glucose.

Vitamin K helps make the proteins needed for blood to clot. With a deficiency of vitamin K, blood doesn't clot.

END OF LECTURE 7A
NUTRI-CHARTS 5 and 6 will be next week (Week 8)