Vitamin A : Deficiency, Supplements, Upper Limit intake, Overdose & Research Studies

(Vitamin A is involved in Gene Regulation and Important for Reproduction)

Recalling Vitamin A

We know that Vitamin A is a fat soluble vitamin, at the same time it is also a powerful antioxidant. Like all antioxidants Vitamin A is helpful in reducing inflammation in fighting with free radical damage. Thus, vitamin A is a source to slow aging naturally. Vitamin A is involved in gene regulation and  important for reproduction. It also helps our heart, lungs, kidneys and other organs work properly.

Deficiency

It is rare now-a-days to have a serious deficiency of vitamin A. Vitamin A deficiency generally not found in industrialized countries, it only found in developing or under developed countries. People who have digestive disorders or very poor diets most likely in a vitamin A deficiency condition. 

Signs & Symptoms

• The first sign of a vitamin A deficiency is often poor sight at night less technically known as night blindness. 
• Prolonged deficiency also lead to dry eye, skin disorders, infections such as measles, diarrhea and lung disorders.
• Vitamin A deficiency also has been shown to impair iron use, as well as impair red blood cell formation.
• Children who are deficient in vitamin A are more likely to develop infections, including measles.

Supplements (Internal & External)

All the multivitamins/minerals contain vitamin A. Other supplements, such as fish liver oil are also high in vitamin A. Vitamin A supplements are generally prescribed by doctor to people who have vitamin A deficiencies. Vitamin A is found in many different therapeutic formulas for example, immune system formula, cold formula, eye health formula, healthy skin formula, acne formula and wellness formula.

• Topical and oral retinoids are commonly prescribed for treating acne, wrinkles, psoriasis, warts, premature aging from the sun and other skin conditions.

  

  Supplements

• Oral vitamin A is also used as a treatment for measles and dry eye in people with low levels of vitamin A. 
• Vitamin A in the palmitate form has been recommended in patients with night blindness.
• Vitamin A supplementation has been shown to raise hemoglobin levels and serum iron concentrations, particularly in children and pregnant women. 
• Vitamin A supplementation has also been shown to enhance the efficacy of iron supplementation in patients with vitamin A deficiency and iron deficiency anemia.
• Ointment with Vitamin A and D, may be useful for sore and cracked nipples that occur during breastfeeding. 
• Vitamin A is also prescribed and used for a specific type of leukemia.

Upper Limit (UL) intake

There is no upper limit for vitamin A from beta-carotene. But if one is taking vitamin A from Retinoids, he/she must keep in mind the Upper Limit (UL) intake.

• Both infants and children in the age of 0 to 3 years can not take more than 600 mcg/day or 2,000 IU/day.
• Children in the age of 4 to 8 years can not take more than 900 mcg/day or 3,000 IU/day.
• Children in the age of 9 to 13 years can not take more than 1,700 mcg/day or 5,610 IU/day.
• Adolescents in the age of 14 to 18 years can not take more than 2,800 mcg/day or 9,240 IU/day.
• Adults in the age of 19 years and up can not take more than 3,000 mcg/day or 10,000 IU/day.

Overdose

High doses of vitamin A along with other antioxidants may actually do more harm than good. 

• Both vitamin A and beta-carotene in overdose may increase triglycerides (fats in the blood). They may even increase the risk of death from heart disease, particularly in smokers.
  
• Fatigue, Muscle and joint pain, Dry skin and lips, Nausea or diarrhea, Hair loss, Vomiting and Headaches are the symptoms of vitamin A overdose. 
• Overdose of vitamin A have been associated with birth defects, lower bone density and liver problems. 
• Alcoholic People or people who have kidney or liver disease shouldn’t take vitamin A supplements unless until his/her doctor recommends.
• When pregnant women take large amounts of vitamin A, they can indirectly harm their unborn babies.
• Overdose of vitamin A may increase the risk of hip fracture or interfere with the beneficial actions of vitamin D.

Research Studies

• As per some research, having more than an average of 1500 mcg/day of vitamin A over many years may affect bones, making them more likely to fracture. This is particularly important for older people, especially Menopausal women, who are prone to osteoporosis.
• A large population study found that people who got high levels of vitamin A though their diets had a lower risk of developing cataracts and supplementing Vitamin A may help slightly slow down the damage from retinitis pigmentosa, a hereditary disease that causes poor night vision.
• Some laboratory studies suggest that vitamin A and carotenoids may help in fighting certain types of cancer because of anti-oxidant properties.
• According to an analysis of multiple studies, Vitamin A supplements overdose consumption, alone or in combination with other antioxidants, results in an increased risk of liver failure, even death.