Vitamin A is an essential nutrient for humans. It does not exist as a single compound but in several forms. Vitamin A is found in many foods; it exists in animal-derived foods as retinol and in plant sources as carotenoids (provitamin A). Foods rich in Vitamin A include liver, egg yolks, butter, milk, cheese, water spinach, amaranth, kale, pumpkin, carrots, and mangoes.
Vitamin A: Benefits, Dosage, and Storage
Benefits of Vitamin A
Vitamin A is a fat-soluble vitamin also known as retinol, commonly used for:
- Treating Vitamin A deficiency;
- Reducing complications from diseases such as malaria, HIV, measles, and diarrhea in children with Vitamin A deficiency;
- Treating heavy menstrual periods, premenstrual syndrome (PMS), vaginal infections, yeast infections, cystic fibrosis of the breast, and helping to prevent breast cancer in women;
- Reducing the risk of HIV transmission to newborns during pregnancy, childbirth, or breastfeeding from HIV-infected mothers;
- Increasing sperm count in men;
- Improving vision and treating eye disorders such as age-related macular degeneration (AMD), glaucoma, and cataracts;
- Treating skin conditions including acne, eczema, psoriasis, herpes, wounds, burns, sunburn, keratosis pilaris, ichthyosis, lichen planus, and pityriasis rubra pilaris;
- Treating digestive ulcers, Crohn’s disease, gum disease, diabetes, Hurler syndrome (mucopolysaccharidosis), sinus infections, hay fever, and urinary tract infections (UTIs);
- Treating Shigella bacterial infections, neurological disorders, nasal infections, loss of smell, asthma, chronic headaches, kidney stones, hyperthyroidism, iron deficiency anemia, hearing loss, and tinnitus;
- Preventing and treating cancer, protecting the heart and cardiovascular system, slowing aging, and boosting the immune system;
- Improving wound healing, reducing wrinkles, and protecting the skin against ultraviolet rays.
Vitamin A is an essential nutrient for humans.
How to Use Vitamin A
When using, you should take retinol as directed on the label or as instructed by your doctor. You can swallow capsules or tablets if using those forms. If using a liquid form, measure the medication with a measuring spoon or a special measuring cup, not with a regular eating spoon. However, be careful not to take more or less than the recommended dose of Vitamin A.
How to Store Vitamin A
You should store it at room temperature, away from moisture and light. Do not store it in the bathroom or freezer. Remember that each medication may have different storage methods. Therefore, read the storage instructions on the packaging carefully or ask your pharmacist. Keep the medication out of reach of children and pets.
You should not dispose of medication down the toilet or drain unless instructed. Instead, dispose of medications properly when they are expired or no longer needed. You can consult your pharmacist or local waste disposal company for safe disposal methods.
Dosage
Dosage for Adults
- Typical dosage for adults with Vitamin A deficiency unrelated to dry eyes: Take 100,000 IU orally or intramuscularly for three days, followed by 50,000 IU daily for two weeks. After two weeks, continue with a daily dose of 10,000-20,000 IU for two months.
- Typical dosage for adults in community intervention programs: Take a single dose of 20,000 IU orally each month for 6 months, 4 months, or 1 month.
- Typical dosage for adults with arthritis: Take 0.5 mg/kg of etretinate (a form of Vitamin A) orally for four weeks, then reduce to 0.25 mg/kg daily if no improvement or side effects occur.
- Typical dosage for adults with breast cancer: Take 1,000-6,000 mg of retinol and 3,000 IU-10,000 IU of Vitamin A daily.
- Typical dosage for adults with stomach and intestinal cancer: Take 5,000 IU and 50,000 IU weekly.
- Typical dosage for adults to reduce cancer-related side effects: Take 100,000 IU of Vitamin A by injection weekly.
- Typical dosage for adults with cervical cancer: Vitamin A supplementation may need to be continued for 1-3 years.
- Typical dosage for adults with colorectal cancer: You may take 25,000 IU of Vitamin A combined with 30 mg of beta-carotene once daily for up to 7 years if ineffective.
- Typical dosage for adults to support HIV infection: Women and newborns immediately after birth may take a large dose of Vitamin A (400,000 IU for adults and 50,000 IU for children) for two years. Pregnant women with HIV should take iron and folate separately or combined with Vitamin A (equivalent to 3 mg of retinol) daily by mouth from weeks 18-28 of pregnancy.
- Typical dosage for adults with liver disease: Take a daily dose of 5,000 IU of Vitamin A for 6 months or 10,000 IU for 4 months.
- Typical dosage for adults with lung cancer: Take 20-50 mg of beta-carotene orally daily or every other day for 5-12 years.
- Typical dosage for adults with psoriasis: You may take a dose of 1 mg/kg daily. Additionally, 10-75 mg of acitretin can be taken orally daily, alone or combined with psoralen and ultraviolet A/B (PUVA/PUVB), and a dose of 1 mg/kg or 75 mg of etretinate can be taken orally daily for six weeks to 12 months.
- Typical dosage for adults for radiation side effects: Take 10,000 IU of retinyl palmitate daily for 90 days.
- Typical dosage for adults with retinitis pigmentosa (visual disorder): Take a dose of 15,000 IU of Vitamin A palmitate daily under medical supervision.
- Typical dosage for adults with skin cancer: Take 100,000 IU of Vitamin A orally daily for 18 months.
Dosage for Children
- Typical dosage for children with acute promyelocytic leukemia: Administer 25-45 mg of all-trans retinoic acid (ATRA) daily.
- Typical dosage for children with anemia: Administer 3,000 mg of Vitamin A orally daily for two months.
- Typical dosage for premature infants with bronchopulmonary dysplasia: Administer 2,000 IU orally daily or 4,000 IU orally three times a week.
- Typical dosage to promote growth in children: Administer 60 mg of Vitamin A, divided into 1-6 doses spaced 4-6 months apart, over 12-104 weeks.
- Typical dosage for children with cystic fibrosis: Administer 3,000 mg of active retinol equivalent (Raes) daily for children over 8 years old.
- Typical dosage for children with malaria: Children aged 6-60 months should receive one capsule (or half a capsule if younger than 12 months) containing 200,000 IU of Vitamin A every three months for 13 months. Dosage for younger children has not been studied and established. Consult a doctor if you plan to use this medication for children.
Vitamin A is available in soft gel capsules and comes in dosages of 5,000 IU, 10,000 IU, and 25,000 IU.
Side Effects
Using Vitamin A may lead to allergic reactions if you are allergic to Vitamin A or any inactive ingredients in the formulation. Seek emergency medical help if you experience any of the following signs: rash; difficulty breathing; swelling of the face, lips, tongue, or throat.
Additionally, Vitamin A may cause some of the following side effects:
- Increased risk of heart disease;
- Bleeding: in the lungs, blurred vision, bone pain;
- Changes in immune function;
- Chronic hepatitis, liver scarring;
- Coughing, fever;
- Nail splitting;
- Chapped lips;
- Reduced thyroid function;
- Depression;
- Diarrhea; feeling of fullness.
Not everyone experiences the above side effects. Other side effects not listed may occur. If you have any concerns about side effects, consult your doctor or pharmacist.
Precautions Before Taking Vitamin A
Before taking Vitamin A, you should:
- Inform your doctor if you are allergic to Vitamin A or any other medications or herbs;
- Inform your doctor if you are taking any medications, herbs, or dietary supplements;
- Inform your doctor if you are pregnant, planning to become pregnant, or breastfeeding.
There are still insufficient studies to determine the risks of using this medication during pregnancy or breastfeeding. Always consult your doctor before taking the medication to weigh the benefits and risks.
Drug Interactions
Drug interactions can alter the effectiveness of medications or increase the risk of side effects. This document does not cover all possible drug interactions. It is best to create a list of all medications you are taking (including prescription drugs, over-the-counter medications, and dietary supplements) to share with your doctor or pharmacist. You should not start, stop, or change the dosage of any medication without your doctor’s approval.
Inform your doctor if you are taking any of the following medications:
- Medications that increase the risk of bleeding, such as aspirin, anticoagulants like warfarin (Coumadin®) or heparin, antiplatelet drugs like clopidogrel (Plavix®), and non-steroidal anti-inflammatory drugs (NSAIDs) like ibuprofen (Motrin®, Advil®) or naproxen (Naprosyn®, Aleve®);
- Medications metabolized by the liver’s cytochrome P450 enzyme system;
- Antidepressants;
- Antidiarrheal medications;
- Cholesterol-lowering medications;
- Medications for stomach issues and gastrointestinal disorders;
- Weight loss medications;
- Anthelmintics;
- Medications affecting the nervous system;
- Medications affecting the liver, alcohol, antibiotics, cancer treatments, antifungals, antimalarials, and antiviral drugs;
- Oral contraceptives, folate, iron salts, mineral oil, nicotine, orlistat, osteoporosis medications, phytonadione (vitamin K), retinoids, dermatological medications, thyroid medications, vaccines, and acids.
Consult your doctor regarding the use of medications with food, alcohol, and tobacco.
Your health condition may affect the use of this medication. You should inform your doctor if you have any health issues.
Foods Rich in Vitamin A
Foods rich in Vitamin A.
Vitamin A is a fat-soluble vitamin, so it is best absorbed when consumed with fat. Foods that are rich in Vitamin A include:
- Carrots
- Sweet potatoes
- Leafy green vegetables
- Pumpkin
- Lettuce
- Watermelon
- Bell peppers
- Seafood
- Mangoes
- Papaya
Note: The information about medications and brand names published in the Family Medicine Cabinet section on the Scimyst.com website is for reference only. Please consult your doctor before deciding to use any medication to ensure effectiveness and safety for your health.
