|
Vitamin A has several important functions in the body, including the maintenance of proper vision. When the body is deficient in Vitamin A, the eye gradually loses its ability to adapt to changes in light resulting in "Night Blindness." Another vital role of vitamin A concerns the formation, maintenance, and growth of skin, which forms the body's primary barrier to infection.
|
What is Vitamin A?
Vitamin A was the first fat-soluble vitamin to be discovered in the early 1900’s. It is also known as preformed vitamin A and retinol, a name used in reference of this nutrients function involving the pigments in the retina of the eye. Retinol (preformed vitamin A) only occurs in foods of animal origin, while fruits and vegetables contain certain carotenoids known as provitamin A.
Vitamin A helps promote healthy surface linings of the eyes, as well as the respiratory, urinary, and intestinal tracts. When these linings break down, it can become easier for bacteria to enter the body and cause infections. It can also help the skin and mucous membranes function as a barrier to bacteria and viruses.
Vitamin A has been shown to play an important role in various bodily functions:
- Vision
- Immunity
- Bone growth
- Reproduction
- Red blood cell production
Additionally, vitamin A is known as an antioxidant. Antioxidants are known to help protect cells from damage caused by unstable substances called free radicals. Free radicals are believed to contribute to certain chronic diseases and play a role in the degenerative disease processes seen in aging.
Vitamin A and Immunity
Modern lifestyles do not always reflect healthy choices and can include poor eating habits, stress, lack of exercise, and environmental chemical exposure. With these types of assaults on a daily basis, it is easy to see how our immune systems can become compromised.
Symptoms of poor immunity can include:
- Increased allergic reactions
- Recurrent colds and flu
- Chronic Fatigue
- Environmental sensitivity
According to Pub Med, “vitamin A and its metabolites are immune enhancers that have been shown to potentiate antibody responses to T cell-dependent antigens, increase lymphocyte proliferation responses to antigens and mitogens, inhibit apoptosis, and restore the integrity and function of mucosal surfaces. Vitamin A and related retinoids may have potential applications in therapy for some infectious diseases.”
Vitamin A Deficiency
Vitamin A deficiency may occur after chronic lack of adequate amounts of vitamin A or beta-carotene.
Taking the RDA level of a nutrient should help prevent a deficiency; however, certain circumstances may require an individual to take higher doses of vitamin A. For example, consumption of alcoholic beverages, taking certain medications such as birth control pills, and those that seize bile production.
Vitamin A can also help the skin and mucous membranes function as a barrier to bacteria and viruses. The PDR for Nutritional Supplements states, “vitamin A deficiency results in decreased resistance to infection.”
A deficiency of vitamin A can result in:
- Hair loss
- Rashes
- Fatigue
- Poor growth
- Dry skin and eyes
- Night blindness
- Loss of appetite
- Neurological symptoms
- Depressed immune function and frequent infections
Those who are malnourished, chronically ill, or recovering form surgery or other injuries may need additional supplementation, as well. Other conditions that can impair vitamin A balance include chronic diarrhea, cystic fibrosis, and kidney disease. Please note: any supplementation for these conditions should be discussed with a health care provider.
Other Uses
Uterine Fibroids
Vitamin A is thought to help hormone glands make adequate amounts of progesterone, which is certainly important for women with estrogen dominance and uterine fibroids caused by this particular hormonal imbalance. Additionally, vitamin A’s anti-infection properties can help protect the integrity of the mucosal lining of the reproductive tract.
Menorrhagia
Heavy menstrual bleeding can be a significant problem for women, especially for those with uterine fibroids and endometriosis. This is the most common reason for hysterectomies. Susan M. Lark, M.D., stated that “in a study of 71 women with excessive bleeding, the women were found to have significantly lower blood levels of vitamin A than the normal population. Almost 90 percent of the women studied returned to a normal bleeding pattern after two weeks of vitamin A treatment. Please consult with a health care provider to help you determine an appropriate dose for you.
Anemia
Heavy bleeding is common amongst those with uterine fibroids and/or hormone imbalances. For many, this type of blood loss can cause one to become anemic. Taking vitamin A (10,000 IU per day) and an iron supplement together has been reported to help overcome iron deficiency more effectively than iron supplements alone. Additionally, adding B-vitamins to this regimen can also be beneficial because they help build red blood cells, which is an important factor when addressing an anemic condition.
Safety of Vitamin A
The condition associated with vitamin A toxicity is called hyper-vitaminosis A, which is caused by overconsumption of preformed vitamin A (retinol). Preformed vitamin A is rapidly absorbed and slowly cleared from the body. Therefore, toxicity from preformed vitamin A may result acutely from extreme high-dose exposure over a short period of time or chronically.
Acute vitamin A toxicity is relatively rare, and symptoms include nausea, headache, fatigue, loss of appetite, dizziness, dry skin, desquamation, and cerebral edema. Signs of chronic toxicity are the same, but also includes dry itchy skin, desquamation, loss of appetite, headache, cerebral edema, and bone and joint pain.
Generally, signs of toxicity are associated with long-term consumption of vitamin A in excess. There is evidence that some populations may be more susceptible to toxicity at lower doses, including the elderly, chronic alcohol users, and some people with a genetic predisposition to high cholesterol. In January 2001, the Food and Nutrition Board (FNB) of the Institute of Medicine set the tolerable upper level of vitamin A intake for adults at 3,000 mcg (10,000 IU)/day of preformed vitamin A.
Further Reading
Vitamin A as an immunomodulating agent
Vitamin A, immunity, and infection
Vitamin deficiency anemia
Supplemental Vitamin A Improves Anemia and Growth…
Supplement Facts
Capsules per Container: 100 Tablets, 10,000 IU
Serving Size: One (1) Tablet
Servings per Container: 100
Suggested Use: 1 tablet daily
Supplement Facts for 10,000 IU Tablet
Serving Size: 1 tablet(s) |
Amount per Serving |
% Daily Value |
| Vitamin A (as palmitate) |
10,000 IU |
200% |
Other Ingredients: microcrystalline cellulose, stearic acid, modified cellulose gum, and colloidal silicon dioxide.
Warning: Women who are pregnant, may become pregnant, or breastfeeding, take only 1/2 tablet daily: do not exceed a total intake of 5,000 IU of pre-formed vitamin A (palmitate) daily and consult your health care professional before using this product. Those taking a prenatal vitamin should take this dosage into account if taking additional vitamin A to be sure the limit is not exceeded.
Do not use if tamper-evident seal is broken or missing. Keep out of reach of children.
Manufactured by Source Naturals
|
Vitamin A Palmitate
Vision Support
by Source Naturals
100 Tablets, 10,000 IU
$3.50 - Discount Price (Retail Price $5.25 - Save 33%)
|
|
