Australia Daily Multi

A multivitamin is one of the few things almost everyone can take safely, which is exactly why it gets oversold. These are the questions our naturopaths ask in store.

A good fit if

• Your eating is patchy and you want a safety net
• You're vegan, or eat very little animal food
• You're pregnant or planning to be, and want your folic acid covered
• You're over 60 and want the type of formula the memory trials actually used
• You'd rather choose RDI-level doses than chase high strength

Check with us first if

• You're pregnant or might be, because of the vitamin A limit and its birth defect warning.
• You're taking B6 from more than one product, because they add up and the upper level is 50 mg a day.
• You smoke or used to, because of the warning signs seen with beta-carotene.
• You take a statin and the formula contains nicotinic acid.
• You're buying for a child, because iron, B6 and several others have age limits.
• You already take single nutrients, so we can check nothing doubles up.

• Standard adult one-a-day. Best known for: General nutritional insurance. Absorption: Not tested separately. The trials measured outcomes, not absorption. Typical use: Around 100% of the RDI for most nutrients. This is the format used in the memory and thinking trials.
• 50+ or senior formula. Best known for: The closest match to the product used in trials. Absorption: Not tested separately. Typical use: Usually more B12 and vitamin D, with the iron taken out.
• Prenatal. Best known for: Folic acid before and during pregnancy. Absorption: Not tested separately. Typical use: 400 to 500 micrograms of folic acid, iodine to the pregnancy RDI, and retinol limited or replaced.
• High-potency or multi-tablet. Best known for: Higher amounts of B vitamins spread across two or three tablets. Absorption: Not tested. Typical use: Seven small trials on stress and energy, without correcting for multiple comparisons.
• Gummies. Best known for: Actually taking it. Absorption: Only single nutrients have been tested: a vitamin C gummy matched a caplet on blood levels, and a vitamin D3 gummy beat a tablet (1,474 vs 774 ng·h/mL). Typical use: They usually leave out iron and cut back minerals for taste. No full gummy multi has been trialled.
• Iron-free. Best known for: Men, and women after menopause. Absorption: Does not apply. Typical use: A formula choice, not a difference in how well it works.
• Liquid or spray. Best known for: Marketed on absorption. Absorption: We found no evidence for either. Typical use: We won't make an absorption claim for these, because nothing supports one.

Reference values. There's no single reference value for a multivitamin, because it's a blend rather than a single nutrient. Each nutrient in it has its own, set by the NHMRC.

Typical supplemental range. One dose a day, at roughly 100% of the RDI for most nutrients. That's the level the trials used, and the level the safety review covers.

Upper level. In Australia, the limits that matter apply to individual nutrients. B6 is capped at 100 mg a day for adults on Australia's permitted ingredients list (Schedule 1), while the NHMRC upper level is 50 mg. Those are two different numbers, so don't mix them up. Selenium from supplements has a 150 microgram daily limit, vitamin A 3,000 micrograms RE, and vitamin D is capped at 25 micrograms in a listed medicine.

Worth knowing. More isn't better here. The evidence is based on RDI-level doses taken consistently, not on high strength. What you need depends on your age, diet and health, so talk to one of our naturopaths in store.

Food first, where the diet allows it.

• A varied diet: the mandatory label statement says it directly: supplements can only be of assistance if dietary intake is inadequate
• B12: animal foods only: the one nutrient with a documented shortfall in vegans across 19 studies
• Iodine: iodised salt, seafood, dairy: capped low in listed medicines, so food matters more here

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

• Pregnancy and vitamin A. Schedule 1 requires a warning that more than 3,000 micrograms retinol equivalents of vitamin A can cause birth defects, and that you should not take vitamin A supplements while pregnant without talking to your doctor or pharmacist first.
• Vitamin B6. Anything above 10 mg a day must carry a warning to stop and see a practitioner if you get tingling, burning or numbness, because nerve damage in the hands and feet (peripheral nerve damage) is the risk. The NHMRC upper level is 50 mg a day, which is below the 100 mg Schedule 1 dose cap, so they are not the same limit.
• Children and iron. Iron is a leading cause of accidental poisoning in small children. Schedule 1 requires child-resistant lids and caps a pack at 750 mg of iron.
• Selenium. The required warning says it is toxic in high doses and that you should not take more than 150 micrograms a day from supplements.
• Zinc above 25 mg a day. It must carry the warning that it may be dangerous in large amounts or over a long period.
• You smoke or used to smoke. Beta-carotene was linked to a higher risk of lung cancer and of death from heart and blood vessel disease. Check whether the vitamin A in your formula is listed as beta-carotene.
• Niacin with a statin. A higher risk of death from any cause was seen with that combination.
• Magnesium at or above 350 mg a day from inorganic salts. It must carry a warning about a laxative effect or diarrhoea. Magnesium oxide medicines must not be labelled for babies under 12 months.
• You take warfarin and want to know about vitamin K. Our sources hold no evidence on this, so we won't give you a number. Ask your prescriber.