Vitamin A Source and its Benefits

Various fruits, vegetables, diary products and animal products form important vitamin A sources, Vitamin D sources, calcium, potassium and zinc sources. Vitamin A was first identified in 1913 and was the first fat-soluble vitamin to be discovered. It’s a light yellow crystalline compound as is also known as retinol. This name is given to it as reference to the participation of this compound in the functions of the retina of the eye. It has also known to be called the anti infective vitamin as it plays an important part in supporting the activities of the immune system. 

Although it is said that animal products is said to the only vitamin A source, a number of fruits an vegetables also contain certain carotenoids that provide vitamin A activity. Some of these fruits and vegetables are carrots, sweet potatoes, spinach, kale, collard greens, turnip greens, winter squash and dried apricots. Carotenoids present in them are plant pigments responsible for the red, orange and yellow color of fruits and vegetables. The body can convert certain members of the carotenoid family including beta-carotene, alpha carotene and gamma carotene into vitamin A. this vitamin is best known for its vital role in vision. It also participates in physiological activities related to the immune system, growth, bone development, reproduction and maintenance of epithelial and mucosal tissues. Dietary deficiency of vitamin A is quite common in developing countries and is associated with high incidences of blindness, viral infections and child mortality that occur in improvised areas. This deficiency primarily affects the health of the skin, hair, immune system and eyes. It can be seen through bone abnormalities and growth retardations. A sign of vitamin A deficiency is Hyperkeratosis, which is a goose bump like appearance of the skin. It is caused by excessive production of keratin that blocks hair follicles. Individuals suffering from insufficient intake of this vitamin often experience increased susceptibility to viral infections, most notably measles, pneumonia and chicken pox. Prolonged vitamin A deficiency can lead to night blindness. 

Excess of Vitamin A can cause a number of problems too. It can cause side effects like loss of appetite, irritability, fatigue, weakness and vomiting. They are usually temporary and caused due to acute ingestion of this vitamin. Chronic vitamin A toxicity in infants can cause growth retardation of long bones like femur bone in the leg and premature epiphyseal bone closing. In adults is can cause conditions like dry and itching skin, brittle fingernails, hair loss, bone and muscle loss. Thus although an important vitamin, vitamin A must be consumed in correct quantities. Vitamin A can be found in animal products like fish oil, lean meat and chicken and calf liver. Fish oil is one of their most important sources and can be found in oily fish like tuna and large prey fish like sharks.