Vitamin A and C

The main function in the body for vitamin a and c are found in our vision and immune system, respectively.

Vitamin A is essesntial for the retina as the metabolite retinal, which regulates scoptic and color vision. In the eye, 11-cis-retinal is attached to rhodopsin and iodospin, commonly know in anatomy as the rods and cones. As light passes through the eye, the cis-retinal is isomerized to the all-trans form. Within this form the all-trans is dissociated from the opsin, which produces a signal along the optic nerve to the brain. Once the signal is sent, the all-trans-retinal is produced back to the 11-cis-retinal form to repeat the cycle. Vitamin A is also important for healthy bones, as long as we consume the correct amount of the correct metabolite. As previously stated, vitamin is found as the metabolite retinal to promote vision. However, too much of this form of vitamin A can trigger an increase in osteoclasts which break down bone mass. In addition, retinal may interfere with the task of vitamin D in preserving bone. On the other hand beta-carotene, another metabolite form of vitamin A, is considered to be safe with no negative impact on bone development. Good sources for vitamin A include animal liver, sweet potatoes, carrots, leafy greens, dried apricots, cantaloupe, and squash.

 

 Vitamin C is used in assisting your immune system in order to prevent diseases and viruses. Physiologically, vitamin C is used as an electron donor for enzymes. The reaction allows hydroxyl groups to bind to amino acids, such as proline and lysine, in the collagen molecule, or the process of hydroxalation. The collagen molecule is then able to keep its triple helix structure which is vital for the production and over seeing of scar tissue, blood vessels and cartilage. In addition, vitamin c also plays an important role in the production of new bones. According to Baylor University researchers, vitamin c suppresses osteoclasts and stimulates osteoblasts. Osteoblasts are key for new bone development, thus making vitamin C a helpful factor in new bone formation. Sources for vitamin C are oranges, lemons, lime, mango, spinach, raspberries, garlic, pineapples, lettuce, pears, and even sunlight!


Sources:
http://students.depaul.edu/~svonk/linkone.html

http://www.niams.nih.gov/Health_Info/Bone/Bone_Health/Nutrition/vitamin_a.asp