Vitamin A 5000iu

With vitamin A, more can do harm. These are the questions our naturopaths ask in store before recommending it.

A good fit if

• Your doctor has found your vitamin A is low
• Your diet is short on both animal foods and orange or green vegetables
• You're choosing a product that keeps you well under 3,000 µg RE a day once food is counted

Check with us first if

• You're pregnant or planning to be. The label warning says not to take vitamin A without asking your doctor or pharmacist.
• You drink alcohol regularly, which makes retinol harder on your liver and interferes with beta-carotene.
• You have liver disease, high blood fats or severe protein malnutrition. The NHMRC says these groups may be especially sensitive.
• You have kidney disease, which can make a blood test read high without reflecting your actual stores.
• You don't absorb fat well, for example with cystic fibrosis or after weight-loss surgery.
• You're older and thinking about your bones, because a high intake of ready-made vitamin A has been linked to hip fracture.
• You use plant sterol spreads or drinks, which lower beta-carotene in your blood.

• Retinol (item 4305). Best known for: The form your body actually uses, and the one doses are measured against. Absorption: Fat-soluble, and carried in the blood by retinol-binding protein. Typical use: The reference form for all vitamin A dose sums, capped at 3,000 µg RE a day.
• Retinol palmitate, sold overseas as retinyl palmitate (item 4307). Best known for: More stable to heat, light and air than plain retinol. Absorption: Turned back into retinol in the gut, so it needs some fat in the meal. Typical use: The usual form in capsules and multivitamins, with the same cap and warnings as retinol.
• Retinol acetate, sold overseas as retinyl acetate (item 4306). Best known for: A shorter-chain ester chosen because it's stable. Absorption: Needs fat in the meal, just like palmitate. Typical use: Common in dry-blend multivitamins. The evidence gives no reason to prefer either ester.
• Beta-carotene (item 855). Best known for: Plant-based, and your body converts it to vitamin A only as needed. Absorption: Varies a lot between people, and goes up with fat in the meal. Typical use: No daily cap and no pregnancy warning, but not for smokers at supplement doses.
• Dunaliella salina, natural beta-carotene (item 1977). Best known for: An algae source of natural mixed carotenoids. Absorption: We have no trial comparing it with synthetic beta-carotene. Typical use: Allowed in listed medicines with no conditions.
• Carotenes (item 1210). Best known for: Allowed only as a colour. Absorption: Not applicable. Typical use: Don't count it as a vitamin A source on an ingredient list.

Reference values. The NHMRC Recommended Dietary Intake is 900 µg RE a day for men and 700 µg for women aged 19 and over. It's 800 µg in pregnancy from 19 to 50, and 1,100 µg while breastfeeding. Children need 300 µg at 1 to 3, 400 µg at 4 to 8, and 600 µg at 9 to 13. Teenage boys need 900 µg and teenage girls 700 µg.

Typical supplemental range. Australian labels show vitamin A in micrograms of retinol equivalents (µg RE), while older overseas labels and most research use IU. As a guide, 2,000 IU of retinol palmitate is about 600 µg RE, and 10,000 IU is about 3,000 µg RE, which is the whole legal daily limit. For beta-carotene, 6 mg gives about 1,000 µg RE.

Upper level. The NHMRC upper limit for ready-made vitamin A from all sources is 3,000 µg a day for adults, or 2,800 µg from 14 to 18. For children, it's 600 µg up to age 3, 900 µg from 4 to 8, and 1,700 µg from 9 to 13. There's no upper limit for beta-carotene. Listed medicines can't go over 3,000 µg RE a day.

Worth knowing. The upper limit includes food as well as supplements, so add what's on the label to what you already eat. A supplement only helps if your diet falls short, and the capsules here are the potent ready-made kind, so more isn't better. What you need depends on your age, diet and health, so talk to one of our naturopaths.

Food first, where the diet allows it.

• Liver: preformed vitamin A; animal foods are the only source of this kind
• Eggs and dairy: preformed vitamin A
• Fish oils: preformed vitamin A
• Orange and dark-green vegetables: beta-carotene, which your body converts as needed
• Plant oils and fruits: provitamin A carotenoids

If any of these sound like you, talk to one of our naturopaths or your doctor before you start.

• You're pregnant or planning a pregnancy. Above 33 µg RE per dose unit, labels must warn you not to take vitamin A without talking to a doctor or pharmacist, and that above 3,000 µg RE vitamin A can cause birth defects.
• You smoke or have been exposed to asbestos and are taking beta-carotene. Two large trials (ATBC and CARET) found higher rates of lung cancer, and of death overall and from heart and blood vessel disease.
• You drink alcohol. Alcohol makes retinol harder on the liver, it interferes with how beta-carotene is converted, and the combination is toxic to the liver.
• You have liver disease, drink heavily, have high blood fats (hyperlipidaemia) or severe protein malnutrition. NHMRC says these groups may be especially sensitive to preformed vitamin A.
• You have chronic kidney disease. Your blood retinol-binding protein is raised, so blood retinol tests can give a misleading picture of your stores.
• Children. Upper Levels are 600 µg up to age 3, 900 µg at 4 to 8, 1,700 µg at 9 to 13 and 2,800 µg at 14 to 18.
• You're an older adult. High dietary total vitamin A (RR 1.29) and retinol (RR 1.23) were linked to more hip fractures.
• You take plant sterols or stanols. 2.5 g a day lowered blood beta-carotene by 16.3%.
• You take more than one product with vitamin A. The adult Upper Level is 3,000 µg a day of preformed vitamin A from all sources.
• If you take prescription medicines, check with your doctor, pharmacist or our naturopaths before you start.