Archive for 'vitamin A'

vitamin A

Posted on 02. Nov, 2010 by .

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Vitamin A, also called retinol, helps your eyes adjust to light changes when you come in from outside and also helps keep your eyes, skin and mucous membranes moist. Vitamin A mostly comes from animal foods, but some plant-based foods supply beta-carotene, which your body then converts into Vitamin A. It also has antioxidant properties that neutralize free radicals in the body that cause tissue and cellular damage. Early information from scientific studies suggests that beta-carotene might help people who already have Coronary Artery Disease (CAD) (ref1) If you’re pregnant, you should avoid eating liver because of the amount of vitamin A it contains. (ref. 2)

Sources of Vitamin A

Top sources of vitamin A include:

• Beef liver

• Egg yolk

• Cheddar cheese

• Fortified milk

Top sources of beta-carotene include:

• Sweet potato

• Carrots

• Pumpkin

• Cantaloupe

• Broccoli

• Apricots

• Spinach and collard greens

Can You Have Too Much or Too Little?

Vitamin A deficiency is rare in the United States, but it can cause night blindness, eye inflammation, diarrhea and other problems. Overconsumption of vitamin A can cause nausea, irritability and blurred vision in its mild form. In addition, the palms of the hands and the bottoms of the feet can turn orange if a person has a high intake of Vitamin A. Vitamin A toxicity can cause growth retardation, hair loss and enlarged spleen and liver in its more severe form. Vitamin A overdose can also cause birth defects and has been linked to increased risk of bone fractures in some people.

Vitamin Storage

If you want to get the most vitamins possible from your food, refrigerate fresh produce, and keep milk and grains away from strong light. Vitamins are easily destroyed and washed out during food preparation and storage. If you take vitamin supplements, store them at room temperature in a dry place that’s free of moisture.(ref. 2)

Recommendations

The best way to get the daily requirement of essential vitamins is to eat a balanced diet that contains a variety of foods from the food guide pyramid.

The Food and Nutrition Board at the Institute of Medicine recommends the following:

Infants

  • 0 – 6 months: 400 micrograms per day (mcg/day)
  • 7 – 12 months: 500 mcg/day

Children

  • 1 – 3 years: 300 mcg/day
  • 4 – 8 years: 400 mcg/day
  • 9 – 13 years: 600 mcg/day

Adolescents and Adults

  • Males age 14 and older: 900 mcg/day
  • Females age 14 and older: 700 mcg/day

Specific recommendations depend on age, gender, and other factors (such as pregnancy). Women who are pregnant or producing breast milk (lactating) need higher amounts. Ask your doctor what dose is best for you.(ref.3)

references and thank you

1 http://www.eatwell.gov.uk/healthydiet/nutritionessentials/vitaminsandminerals/vitamina/

2 http://www.lifeclinic.com/focus/nutrition/vitamin-a.asp

3http://www.nlm.nih.gov/medlineplus/ency/article/002400.htm

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