There are 13 essential vitamins that the body needs and they are broken into two types: water and fat soluble. Vitamins are organic substances required for normal cell function, growth and development. Water-soluble vitamins travel freely through the body, are absorbed directly by cells and excess amounts are usually excreted by the kidneys through urine. These vitamins should be taken in frequent and small doses. They are not as likely as fat soluble vitamins to reach toxic levels. Fat-soluble vitamins are stored in the body’s cells and are not excreted as easily as water-soluble vitamins. They do not need to be taken as often but adequate amounts are needed. Taking too much can be toxic. They bind to fat in the stomach and are then stored in the liver for later use.
VITAMIN A
Retinol
Retinal
Retinoic acid
Beta carotene can easily be converted to vitamin A as needed
Fat soluble
Best plant food sources
Retinoids
Vegetables: dark leafy greens
Beta carotene
Fruits: yellow and orange fruits (apricot, cantaloupe, mango)
Vegetables: carrots, chilies, broccoli, dark leafy greens (turnip greens, kale, spinach), pumpkin, squash (butternut, acorn), sweet potatoes, yellow/orange vegetables
Grains: fortified cereal
Function in the body
Supports immune system, helps the body resist infection
Supports reproductive system and fetal development
Antioxidant
Supports growth and repair of body tissues
Maintains integrity of white and red blood cells
Maintains stability of cell membranes, healthy skin, mucous membranes
Needed for the formation of bones and teeth
Needed for good eyesight (especially night vision)
Helps the heart, lungs, kidneys work properly
Health Benefits
Reduces risk of cancer (lung, prostate, skin)
Protects against cataracts
Reduces risk of heart disease
Lowers cholesterol
Slows down age-related macular degeneration
Lowers risk of death from measles and shortens fever and diarrhea
Symptoms of deficiency
Night blindness
Complete blindness
Diarrhea
Groups at risk of being deficient
Infants, young children, pregnant and breastfeeding women in developing countries
People with cystic fibrosis
Excess intake
Large amounts of supplemental vitamin A (but not beta carotene) can be harmful to bones
Other notes
Can build up during pregnancy and cause birth defects
Requires a little bit of fat for absorption