The CalorieKing Vitamin Guide

Vitamins are chemical compounds that are essential for normal growth and metabolism; you need them to keep healthy.

The main role of vitamins is to help convert the food you eat into energy and living tissues such as bones, muscles, blood, nerves and skin – without them, you would fall apart! Vitamins also help the body resist infection and protect body cells. Although vitamins are essential to life, they are only required in tiny amounts. 

Because vitamins cannot be made by the body (except vitamin D), you have to get them from food. Most vitamins are not stored in the body to any great extent and must be replenished regularly, which is why it’s so important to eat a well-balanced diet.

New research also suggests a greater role for vitamins (and minerals) in the prevention or slowing down of many diseases such as heart disease, cancer, cataracts, osteoporosis and birth defects. The total effects of vitamins on the body are still not fully known or understood.

There are two broad groups of vitamins:

• Fat-soluble vitamins including vitamins A, D, E, K, and beta-carotene
• Water-soluble vitamins including the B vitamins, (B1, B2, B3, B6, B12) vitamin C, and folate.

Vitamin supplements can be useful for people who cannot obtain sufficient amounts from food – perhaps as a result of illness or special dietary requirements.

However, there are many other nutritional factors with vitamin-like qualities that can only be obtained by eating a wide variety of foods. Vitamin supplements are not a substitute for a healthy diet.

Large doses of vitamins or minerals can also have drug-like effects and should only be taken under medical supervision.

RDAs are the amounts of essential nutrients that are considered adequate to meet the nutritional requirements of healthy people. They are designed to prevent nutritional deficiency diseases such as scurvy, beriberi, pellagra, rickets and anemia. Following RDA recommendations for vitamins and other nutrients helps keep your body in good health.

However, it’s important to remember that the RDAs do not address the extra nutrient needs of people who have certain chronic ailments, who smoke, or who are on prescribed medication. 

To find out RDAs for specific vitamins, click on the related article links at the end of this article.

Many people are vulnerable to nutritional deficiencies and need to take extra care to improve the quality of their diet. Supplements can also be taken to boost nutrients in the body. People at risk for vitamin deficiency include:

• Elderly people who: are light eaters; find preparation and cooking of food an effort; are unable to chew or swallow properly; are on prescribed medications which may reduce appetite or increase vitamin/mineral needs.
  
  
• Teenagers & young adults who lead erratic lifestyles and tend to eat haphazardly.
  
  
• Women who: are on oral contraceptives; have heavy menstrual blood losses; suffer from osteoporosis; are pregnant or breast-feeding; have premenstrual syndrome; have sports anemia. Note: Pregnant women should never take supplements containing vitamin A.
  
  
• Cigarette smokers in particular require extra vitamins; e.g. vitamin C and E, beta-carotene.
  
  
• Many heavy drinkers lack B vitamins, vitamin C, magnesium and zinc. Heavy alcohol intake encourages poor dietary habits.
  
  
• Dieters, dancers and models who overly restrict quantity and variety of foods.
  
  
• People on long-term medication. Many commonly-prescribed drugs can interfere with nutrient absorption and metabolism. Alcohol and coffee can also interfere with the absorption of nutrients.
  
  
• Vegans may lack vitamin B12 and iron.
  
  
• People with intestinal malabsorption may suffer deficiencies.
  
  
• People with chronic ailments. Medically-directed supplementation may benefit many medical conditions. (Do not stop your current medication unless directed by your doctor.)

Although vitamins are important for your body, more is not always better. In fact, it’s very easy to overdose on vitamins by taking supplements, even to toxic levels. Before taking a supplement, do the research and talk to your doctor about whether you really need it. Always be aware of toxicity levels for the supplements you are taking. Usually, a multi-vitamin is a safe bet – even so, it pays to check.

For information about toxicity of specific vitamins, click on the links below. Note: Pregnant women should never take supplements containing vitamin A.

Getting the vitamins you need from your food, rather than supplements, is the best approach. However, as the vitamin content of food can be decreased depending on the way the food is handled, stored, and cooked, follow these tips for keeping foods as vitamin-packed as possible! 

• The longer the storage period, the greater the vitamin loss. Shop more frequently for fresh fruits and vegetables. Frozen vegetables and fruits are fresher and retain their nutrients longer than poorly stored “fresh” produce. Avoid dehydrated vegetables.
  
  
• Oxygen can destroy some vitamins, so avoid buying pre-cut produce and cut up fresh produce at the last moment. Avoid thawing frozen vegetables before cooking.
  
  
• Scrub vegetables clean rather than peeling them.
  
  
• Use minimum amounts of water in cooking to avoid loss of water-soluble vitamins, B & C, and leeching out of minerals. Cook vegetables whole or in large chunks to lessen the surface area exposed.
  
  
• Cooking methods which are quick and limit exposure of foods to high temperatures are preferable; e.g. steaming, stir-frying and microwaving.
  
  
• Cook vegetables until they are softened but still crispy and colorful.
  
  
• For the freshest produce available, grow your own vegetables. Tending your own garden can be fun and fulfilling.
  

Different vitamins play different roles in keeping your body healthy. For example, vitamin A helps with night vision, resistance to infection and even sperm production; vitamin B1 maintains muscle tone; and vitamin C helps aid iron absorption. There are literally hundreds of other examples.

To learn more about a particular vitamin, why it’s important for your health and well-being, which foods contain it, and how much you need of it, click on a related article link below.