Vitamin A (Beta-carotene, Retinol)

BASIC INFORMATION

Beta-carotene is a previtamin-A compound found in plants. The
body converts beta-carotene to vitamin A.
Brand names:
Vitamin-A Capsules
Afaxin(R)
Alphalin(R)
Aquasol A(R)
Vitamin-A Oral Solution
Aquasol A(R)
Vitamin-A Tablets
Available from natural sources? Yes
Available from synthetic sources? Yes
Prescription required? No
Fat-soluble or water-soluble: Fat-soluble

NATURAL SOURCES

Apricots, fresh
Asparagus
Broccoli
Cantaloupe
Carrots, sliced
Endive, raw
Kale
Leaf lettuce
Liver
Mustard greens
Pumpkin
Spinach
Squash, winter
Sweet potatoes
Watermelon

REASONS TO USE

Aids in treatment of many eye disorders, including prevention of night blindness and formation of visual purple in the eye.

Promotes bone growth, teeth development, reproduction.

Helps form and maintain healthy skin, hair, mucous membranes.

Builds body's resistance to respiratory infections.

Helps treat acne, impetigo, boils, carbuncles, open ulcers when applied externally.

UNPROVED SPECULATED BENEFITS

Helps control glaucoma.

Buffers against cancer.

Guards against effects of pollution and smog.

Cushions against stress.

Speeds healing.

Helps in removal of age spots.

Fights infections.

Fights skin diseases.

Shortens duration of some illnesses.

WHO NEEDS ADDITIONAL AMOUNTS?

Anyone with inadequate caloric or nutritional dietary intake or increased nutritional requirements.

Pregnant or breast-feeding women.

Those who abuse alcohol or other drugs.

People with a chronic wasting illness, excess stress for long periods or who have recently undergone surgery.

Those with a portion of the gastrointestinal tract surgically removed.

People with recent severe burns or injuries.

DEFICIENCY SYMPTOMS

Night blindness

Lack of tear secretion

Changes in eyes with eventual blindness if deficiency is severe and untreated

Susceptibility to respiratory infection

Dry, rough skin

Changes in mucous membranes

Weight loss

Poor bone growth

Weak tooth enamel

Diarrhea

Slow growth

UNPROVED SPECULATED SYMPTOMS

Bone thickening

Kidney stones

Diarrhea

Birth defects

Reduced production of steroid hormones

LAB TESTS TO DETECT DEFICIENCY

Many months of deficiency required before lab studies reflect
deficiency.

Plasma vitamin A and plasma carotene

Dark-adaptation test

Electronystagmogram

Electroretinogram

DOSAGE AND USAGE INFORMATION

Recommended Dietary Allowance (RDA):
Estimate of adequate daily intake by the Food and Nutrition
Board of the National Research Council, 1980. See Glossary.
RDA for vitamin A is expressed in retinol equivalents (RE).
One RE = 1mcg retinol or 6mcg beta-carotene. IU = International
units.
Retinol International

Age Equivalents	Units
0-6 months 420RE	2,100IU
6-12 months 400RE	2,100IU
1-3 years 400RE	2,000IU
4-6 years 500RE	2,500IU
7-10 years 700RE	3,300IU
MALES
11+ years 1,000RE	5,000IU
FEMALES
11+ years 800RE	4,000IU
Pregnant +200RE	+1,000IU
Lactating +400RE	+2,000IU

What this vitamin does:

Essential for normal function of retina. Combines with red pigment of retina (opsin) to form rhodopsin, which is necessary for sight in partial darkness.

May act as co-factor in enzyme systems.

Necessary for growth of bone, testicular function, ovarian function, embryonic development, regulation of growth, differentiation of tissues.

Miscellaneous information:

Many months of a vitamin-A-deficient diet are required before symptoms develop. Average person has a 2-year supply of vitamin A stored in the liver.

Steroids are produced by the adrenal gland and are part of the natural response to stress and immune function. Failure to make these important hormones leaves immune system in a less-than- ideal atate.

Available as:

Extended-release capsules or tablets: Swallow whole with full glass of liquid. Don't chew or crush. Take with or immediately after food to decrease stomach irritation.

Oral solution: Dilute in at least 1/2 glass water or other liquid. Take with meals or 1 to 1-1/2 hours after meals unless otherwise directed by your doctor.

A constituent of many multivitamin/mineral preparations.

Some forms available by generic name.

WARNINGS AND PRECAUTIONS

Don't take if you:

Are allergic to any preparation containing vitamin A.

Consult your doctor if you have:

Cystic fibrosis

Diabetes

Intestinal disease with diarrhea

Kidney disease

Liver disease

Overactive thyroid function

Disease of the pancreas

Over age 55:

More likely to be malnourished and need supplement.

Dosage must be taken carefully to avoid possible toxicity.

Pregnancy:

Daily doses exceeding 6,000 IU can produce growth retardation and urinary-tract malformations of fetus.

Don't take megadoses.

Breast-feeding:

Don't take megadoses.

Effect on lab tests:

With chronic vitamin-A toxicity, lab tests show INCREASED blood glucose, blood-urea nitrogen, serum calcium, serum cholesterol, serum triglycerides.

Poor results on dark-adaptation test (See Glossary)

Poor results on electronystagmogram (See Glossary)

Poor results on electroretinogram (See Glossary)

Storage:

Store in cool, dry place away from direct light, but don't freeze.

Store safely out of reach of children.

Don't store in bathroom medicine cabinet. Heat and moisture may change action of vitamin.

Others:

Children are more sensitive to vitamin A and are more likely to develop toxicity with dosages exceeding the RDA.

Toxicity is slowly reversible on withdrawal of vitamin A but may persist for several weeks.

OVERDOSE/TOXICITY

Signs and symptoms:
Bleeding from gums or sore mouth, bulging soft spot on head in
babies, sometimes hydrocephaly ("water on brain"), confusion or
unusual excitement, diarrhea, dizziness, double vision,
headache, irritability, dry skin, hair loss, peeling skin on
lips, palms and in other areas, seizures, vomiting, enlarged
spleen and liver.
NOTE: Toxicity symptoms usually appear about 6 hours after
ingestion of overdoses of vitamin A. Symptoms may also develop
gradually if overdose is milder and over a long period of time.

What to do:

For symptoms of overdosage: Discontinue vitamin, and consult doctor. Also see ADVERSE REACTIONS OR SIDE EFFECTS section below.

For accidental overdosage (such as child taking entire bottle): Dial 911 (emergency), 0 for operator or your nearest Poison Control Center.

ADVERSE REACTIONS OR SIDE EFFECTS

Reaction or effect	What to do
Abdominal pain	Discontinue. Call doctor
	immediately.
Appetite loss	Discontinue. Call doctor when
	convenient.
Bone or joint pain	Discontinue. Call doctor
	immediately.
Discomfort, tiredness or weakness Discontinue. Call doctor when
	convenient.
Drying or cracking of skin or	Discontinue. Call doctor
lips	immediately.
Fever	Discontinue. Call doctor
	immediately.
Hair loss	Discontinue. Call doctor
	immediately.
Headache	Discontinue. Call doctor when
	convenient.
In children, premature closure	Discontinue. Call doctor
of epiphyses (the end parts of	immediately.
bones where growth occurs from
birth through adolescence)
Increase in frequency of	Discontinue. Call doctor when
urination	convenient.
Increased sensitivity of skin	Discontinue. Call doctor when
to sunlight	convenient.
Irritability	Discontinue. Call doctor
	immediately.
Vomiting	Seek emergency treatment.
Yellow-orange patches on soles	Seek emergency treatment.
of feet, palms of hands or skin
around nose and lips

INTERACTION WITH MEDICINE, VITAMINS OR MINERALS

Interacts with	Combined effect
Antacids	Decreases absorption of
	vitamin A and fat-soluble
	vitamins D, E, K.
Anti-coagulants	Increases likelihood of
	spontaneous or hidden
	bleeding.
Cholestyramine, colestipol	Decreases absorption of
	vitamin A.
Mineral oil, neomycin,	Increases likelihood of
sucralfate, isioretinoin	vitamin-A toxicity.
Oral contraceptives	Increases vitamin-A
	concentrations.
Vitamin E	Normal amount facilitates
	absorption, storage in liver
and utilization of vitamin A.
Excessive dosage may deplete
vitamin-A stores in liver.

INTERACTION WITH OTHER SUBSTANCES

Tobacco decreases absorption. Smokers may need supplementary vitamin A.

Chronic alcoholism interfers with the body's ability to transport and use vitamin A.