Nutrition: Micronutrients

What are Micronutrients?

Vitamins and minerals are substances the body needs in small but steady amounts for normal growth, function and health. Together, vitamins and minerals are called micronutrients. The body cannot make most micronutrients, so it must get them from foods or dietary supplements.

Vitamins

Vitamins must be absorbed from food because the body cannot make them. The body only needs small amounts of vitamins (that's why they are referred to as micronutrients) and uses them without breaking them down. Vitamins are needed for a variety of body functions to include muscle and skeletal health, food digestion and nerve function. Vitamins are involved in many bodily processes that use carbohydrates, fats and proteins for energy and repair.

There are thirteen compounds classified as vitamins. Vitamins A, D, E and K are fat-soluble vitamins. They accumulate in the body and have a long body retention time. Vitamin C and the eight B vitamins (biotin, folate, niacin, pantothenic acid, riboflavin, thiamin, vitamin B6, and vitamin B12) are water-soluble. They do not accumulate in the body because excess amounts consumed are readily excreted by the kidney. Vitamins are labeled by "letter" or name, and some common vitamins include:
Vitamin A = retinol, retinaldehyde, retinoic acid
Vitamin B1 = thiamin
Vitamin B2 = riboflavin
Vitamin B3 = niacin, nicotinic acid
Vitamin B12 = cobalamin
Vitamin C = ascorbic acid
Vitamin D = calciferol
Vitamin E = tocopherol, tocotrienol
Vitamin K = phylloquinone

hide

Minerals

These micronutrients include calcium, magnesium and phosphorus. They are the main components in teeth and bones and also serve as building blocks for all cells, help regulate body fluids, and are involved in nerve impulses and muscle function.

hide

Food labels

If you eat a healthy diet, do you need to take vitamins? Not long ago, the answer from most experts would have been a resounding "no.” The reason was that by eating a well balanced variety of foods one more than likely would consume all of the vitamins and minerals needed for health. Nutritious eating includes:
• Eating a variety of foods, including vegetables, fruits and whole-grain products.
• Eating lean meats, poultry, fish, beans and low-fat dairy products.
• Limiting consumption of salt, sugar, alcohol, saturated fats and trans fats.
• Reading food labels to ensure a healthy diet.
One model for a “balanced” and nutritious meal would be to use the "plate method" for planning food portions:
• 50 percent as assorted vegetables
• 25 percent as protein
• 25 percent as whole grains (e.g., brown rice)
• One fruit
hide

Vitamin deficiencies

Fat soluble vitamins may be deficient in diseases of malabsorption such as Celiac disease (sprue), cystic fibrosis, chronic pancreatitis, inflammatory bowel disease or short bowel from multiple bowel resections. Water soluble vitamin deficiencies are uncommon, but may be seen in wasting states (cancer, HIV, etc.), or after gastric bypass surgery during rapid weight loss and non-compliance with vitamin intake. Vitamin and mineral deficiencies may cause the following signs or symptoms:
Vitamin A = difficulty seeing at night, xerophthalmia (corneal erosions and scarring), dry skin
Vitamin B1 = double vision (nystagmus, ophthalmoplegia), impaired gait, confusion, memory loss
Vitamin B2 = anemia, dermatitis, sore throat-mouth-tongue
Vitamin B3 = vomiting, hyperpigmented rash, diarrhea, disorientation-delusions-dementia
Vitamin B12 = anemia, abnormal gait and balance, impaired memory and irritability, dementia
Vitamin C = scurvy (poor wound healing, bleeding gums, petechiae, arthralgias, hyperkeratosis)
Vitamin D = osteomalacia or rickets (in children), bone loss, muscle weakness or spasm
Vitamin E = abnormal gait and balance, muscle weakness, neurologic abnormalities
Vitamin K = poor blood clotting, skin bruising

hide

Tags:

Nutrition

Obesity