Are you taking Vitamin A in your Diet ??

Vitamin A is commonly known as the vitamin needed for good eyesight. Along with promoting vision, vitamin A is also vital for regulating genes, maintaining healthy skin, supporting the immune system and producing red blood cells.It is connected with skeletal growth and protects the body against microbial infection.

There are several forms of Vitamin A that are needed by the body. These include:

• Retinal – a metabolite of vitamin A required for vision.
• Rentinol – the form of vitamin A that can be stored by the body and converted to retinal when needed.
• Retinioc acid – a growth factor needed primarily to regulate genes.

Daily Requirement

Recommended Dietary Allowance (RDA) for vitamin A are given as mcg of retinol activity equivalents (RAE) to account for the different bioactivities of retinol and provitamin A carotenoids . Because the body converts all dietary sources of vitamin A into retinol, 1 mcg of physiologically available retinol is equivalent to the following amounts from dietary sources: 1 mcg of retinol, 12 mcg of beta-carotene, and 24 mcg of alpha-carotene or beta-cryptoxanthin. From dietary supplements, the body converts 2 mcg of beta-carotene to 1 mcg of retinol.

Currently, vitamin A is listed on food and supplement labels in international units (IUs). Conversion rates between mcg RAE and IU are as follows:

• 1 IU retinol = 0.3 mcg RAE
• 1 IU beta-carotene from dietary supplements = 0.15 mcg RAE
• 1 IU beta-carotene from food = 0.05 mcg RAE
• 1 IU alpha-carotene or beta-cryptoxanthin = 0.025 mcg RAE

An RAE cannot be directly converted into an IU without knowing the source(s) of vitamin A. For example, the RDA of 900 mcg RAE for adolescent and adult men is equivalent to 3,000 IU if the food or supplement source is preformed vitamin A (retinol). However, this RDA is also equivalent to 6,000 IU of beta-carotene from supplements, 18,000 IU of beta-carotene from food, or 36,000 IU of alpha-carotene or beta-cryptoxanthin from food. So a mixed diet containing 900 mcg RAE provides between 3,000 and 36,000 IU of vitamin A, depending on the foods consumed.

Recommended Dietary Allowances (RDAs) for Vitamin A -

Age	Male	Female	Pregnancy
0–6 months*	400 mcg RAE	400 mcg RAE
7–12 months*	500 mcg RAE	500 mcg RAE
1–3 years	300 mcg RAE	300 mcg RAE
4–8 years	400 mcg RAE	400 mcg RAE
9–13 years	600 mcg RAE	600 mcg RAE
14–18 years	900 mcg RAE	700 mcg RAE	750 mcg RAE
19–50 years	900 mcg RAE	700 mcg RAE	770 mcg RAE
51+ years	900 mcg RAE	700 mcg RAE

You don't have to get the recommended amount of vitamin A every day. Instead, aim for that amount as an average over the course of a few days or a week.

Sources of Vitamin A

Vitamin A is found in dark green and yellow vegetables and yellow fruits, such as broccoli spinach, turnip greens, carrots, squash, sweet potatoes, pumpkin, cantaloupe, and apricots, and in animal sources such as liver, milk, butter, cheese, and whole eggs.

Deficiency Diseases Of Vitamin A-

The important deficiency states due to lack of vitamin A in the diet are:

• Night Blindness: In the early stages of vitamin A deficiency, the individual cannot see well in dim light. In advanced deficiency, the subject cannot see objects in dim light.
• Xerosis Conjunctiva: The conjunctiva is dry, thickened, wrinkled and pigmented. The pigmentation gives conjunctiva a smoky appearance.
• Xerosis Cornea: When dryness spreads to cornea, it takes on a hazy, lusterless appearance.
• Bitot’s Spots: Greyish glistening white plaques, formed of desquamated thickened conjuctival epithelium, usually triangular in shape and firmly adhering to the conjuctiva.
• Keratomalacia: When xerosis of the conjuctiva and cornea is not treated, it may develop into a condition known as keratomalacia.
• Follicullar Hyperkeratosis: The skin becomes rough and dry.