Vitamins are substances to grow and develop your body. Your body requires 13 vitamins. They are-
- Vitamin A
- B vitamins (thiamine, riboflavin, niacin, pantothenic acid, biotin, vit. B-6, vit. B-12, and folate )
- Vitamin C
- Vitamin D
- Vitamin E
- Vitamin K
- Absorbed with nutritional fat in the tiny intestine
- 40-90 percent energy efficiency
- Absorption typically controlled by the need
- need to absorb
- Transported by blood and lymph from the tiny intestine in chylomicron (depending on size)
- They are not readily excreted by the urine.
- Significant quantities are stored in the tissue of the liver and fat.
- Toxicity is thus feasible.
Vitamin A is a vitamin that is fat-soluble and therefore needs to be eaten with fat for ideal absorption. High vit. A Includes foods are carrots, lettuce, dark leafy greens, sweet potatoes, winter squash, dried apricots, cantaloupes, bell peppers, fish, liver, and tropical fruits.
Role in a vision: Vit. A (retinal) is an important precursor to visual pigment formation, rhodopsin, in the eye’s retina. In vision, particularly night vision, Retinal plays a significant role. Reduces the incidence of cataracts.
Role in growth: Helps to control the growth of cells, differentiation of cells and division of cells.
Role in Bone and teeth formation: Promotes adequate bone and teeth development. Bone cells are dependent on vit (osteoblasts and osteoclasts). A for their ordinary operation.
Is essential for good hair, skin and mucous membranes to be formed and maintained. Strengthens the immune system of the body to help boost the resistance of the body to infectious diseases.
Problems associated with Vitamin A
Vit. A deficiency:
- “Night blindness”-the first detectable sign of vit. A deficiency. Inability to see a flash of bright light in dim light or failure to regain vision.
- Increased susceptibility to iron-deficient, infection, and cancer as well as anemia.
- Long-standing absence of vit. A (corneal keratinization, a disease called xerophthalmia).
- Abnormal fetal and neonatal growth of the bone.
Vit. A excess:
Hypervitaminosis A in humans-
Symptoms include dry, pruritic skin with excessive itching and intracranial pressure rise.
Because of self-medication and over-prescription, hypervitaminosis A is becoming a growing issue in Western nations.
has occurred by eating polar bear or seal liver which contains very high vit A, by polar explorers.
Sparingly eat polar bear liver, 30 grams of retinol comprise 450,000 IU! Continued intake leads the skin to peel from head to toe.