What are they?
Vitamins are organic substances, required by your body to perform specific tasks that promote good health. Unlike the energy nutrients, protein, fats and carbohydrates, they do not have calories and are single molecules that are not linked together.
They must be obtained from your diet and are, as the name suggests, “vital” for good health. Relatively small amounts are needed to achieve a healthy eating lifestyle.
Scientists generally divide vitamins into two categories—water-soluble and fat-soluble. The water-soluble ones are the B's and C. The fat-soluble ones are A, D, E , K.
For specific information on each, please click on the links below.
Water-soluble vitamins, as the name suggests, can be dissolved in water, so they are absorbed directly into your blood stream. They travel freely though the blood to the sites in your body where they are needed and any excess can be removed by the kidneys and excreted through the urine.
Fat-soluble vitamins, because they cannot dissolve in water, must be absorbed through the lymph and then be transported in the blood by protein carriers. Any excess is stored in the fat storage areas of your body.
Some nutrients are available from your food in the form of a “precursor.” This is an inactive form that can be converted by your body to the active form. An example of this is the beta-carotene found in carrots and other yellow, orange and dark green, leafy vegetables. If needed, your body can convert beta-carotene to Vit A.
They can be destroyed
Vitamins in foods can be destroyed by light, heat and oxygen. Storage methods and food preparation techniques will affect the amount retained by the foods. To minimize this problem, refrigerate produce in airtight containers, and during preparation, steam or cook vegetables lightly, avoiding high temperatures and extended cooking times whenever possible.
Vitamins are essential to good health.
From the time you were a kid and your mom gave you those cute pills shaped like cartoon characters, you probably realized that you need vitamins to be healthy. In fact, when the subject comes up, many people still think of pills, not food.
It is generally agreed that the best way to get nutrients in in your diet is from the foods you eat. Even if you take a supplement, the idea is to do just that—supplement—the foods in your diet, not replace them.
The nutrients in food seem to be more accessible to your body, than those from pills because they are not isolated, but surrounded by other substances that work with them to keep you healthy. This is not to say you should not take a supplement; many health experts recommend that you do. However, do not make the mistake of thinking that a pill can replace nutritious whole foods in your diet.
Vitamins are found in varying degrees in all of the food groups.
Fruits… Vegetables… Cereals… Grains… Meat and other Protein foods… Dairy products… Fats and oils…
Fat-soluble or water-soluble vitamins differ in how they are handled in your body. The significance of this to you is that since the fat-soluble ones can be stored for later use, you probably don’t need to worry as much about a deficiency. However, they also can be more toxic because of the very fact that your body does not excrete the excess.
The water-soluble ones must be obtained almost daily, since your body will excrete the excess each day. By the same token, they are less likely to become toxic, although it is still possible if you take very large doses.
When vitamins that can be obtained from precursors such as beta-carotene, your body can convert what is needed and the rest of the precursor can be excreted. In this way, there is also less chance of toxicity.
Enriched and fortified
Many products that we eat are enriched or fortified with nutrients. That is, nutrients are added to the food either to replace those removed in processing or to make the food more nutritious.
Most milk has Vit A and/or D added. White flour is enriched with B's, as are many white flour products, such as cereals, bread and pasta. Many juice drinks are fortified with Vit C.
How much do I need?
The RDA (Recommended Dietary Allowance) for nutrients varies based on age and gender, with a separate recommendation for pregnant and lactating women. It is difficult to say exactly how much is needed because there are so many variables besides the obvious ones of age and gender.
Each of us is a unique individual, and the availability of nutrients from the foods we eat, or even from a supplement will vary based on individual factors. The amount we absorb can be affected by our overall health and nutritional status. It can also be affected by how the food is stored and prepared and by foods that we eat at the same time. The RDA tries to take all of these factors into account, but it is still, at best, a general guideline.
--Caveat: If you eat a diet that is too high in fiber, the food will literally race through your digestive system, not allowing much time for absorption of the nutrients you need.
For the specific RDA, please click on the link for that vitamin.
While the RDA may be useful in a scientific sense, or if you are comparing labels on the foods or supplements you purchase, the best way to insure that you are getting enough, is to eat a variety of nutritious whole foods. Selecting foods from all of the food groups will help ensure that you have all of your bases covered.
Having said that, many health experts recommend that you take a daily supplement just to be sure that you are getting enough of these nutrients.
--Caveat: As with anything, you can get too much of a good thing. Don’t overdue on supplements. Your body can handle excess to a point, but beyond that, vitamins can become toxic. Toxicity is not likely to occur if you get your nutrients from food.
Why do I need them?
You need vitamins to be healthy and to feel good. Together with the other nutrients, Protein, Carbohydrates, Fats, Minerals and Water, they help keep your body working properly. Each one has a significant role to play in the your total good health.
Can I get too much?
All nutrients, even water, can be toxic if you overdo. In the case of vitamins, because of supplementation with pills, there is a greater potential for getting too much. If you get them from food, toxicity is very rare. If you supplement with pills, be aware of the dose and realize that vitamins can become toxic if taken in mega doses.
Eat a variety of fresh, whole foods. Store vegetables and fruits properly. If you cook vegetables, cook them lightly whenever possible. Eat foods from all of the food groups daily. Supplement with a good multi-vitamin, from natural sources, to fill in the gaps.
It’s as simple as that!