Bluebonnet Nutritions

Vitamins differ from macronutrients like carbohydrates, proteins and fats by virtue of the amount required. Typically, minuscule amounts are needed in comparison. Plus, vitamins are not used as an energy source. Instead, they are critical for the normal functioning, growth, repair and maintenance of cells and tissues and are required in individual units rather than long chains of smaller units. However, like carbohydrates, proteins and fats, vitamins are organic compounds, meaning that they are carbon-containing and are essential to one's overall well-being. In fact, a deficiency of just one vitamin can have a profound effect on the body and health.

Vitamins A & D

Vitamin A refers to a family of fat-soluble retinoids, which include retinol, retinal and retinoic acid, plus provitamin A carotenoids, such as beta-carotene. They perform three basic functions within the body: vision, the growth and development of many types of tissues, and immunity. Several different cells in the eye (retina, cornea and the epithelium) depend on the presence of vitamin A for the maintenance of the structural integrity of these cells for optimal visual health. Dietary sources high in vitamin A include beef liver, carrots, sweet potato, chicken liver, spinach, fortified milk, mangos and collard greens.

Vitamin D is a fat-soluble nutrient that requires conversion in the liver and kidneys to form the physiologically active form of vitamin D, calcitriol. Active vitamin D functions in the body as a hormone; however, its function to increase calcium absorption, which helps form and maintain healthy bones and teeth, is one of the most significant. The other physiological functions of vitamin D include maintenance of normal blood levels of calcium and phosphorus.

There are two forms of vitamin D: D2 and D3. Vitamin D2 (ergocalciferol) is found in yeast and plants that have been exposed to ultraviolet light. Vitamin D3 (cholecalciferol), however, is found in animal products and is also made in the body when sunlight triggers its synthesis in the skin.

B Vitamins

The scientists who first discovered vitamin B believed that it was a single compound; however, with the advances in technology, it was soon discovered that it was a family of eight water-soluble compounds. Today, with the exception of B6 and B12, B vitamins are referred to by their names: thiamin (B1), riboflavin (B2), niacin (B3), pantothenic acid (B5), biotin and folate. Exceptional dietary sources of B vitamins include fortified cereals, ham, tuna, wheat germ, liver, milk, spinach, lentils and a wide variety of other foods.