Sustained Release Multi + Antioxidants

The word on the front tells you very little, so these are the questions our naturopaths ask in store to match you to the one ingredient that fits.

A good fit if

• You want a specific antioxidant for a specific reason, and you're happy to read the ingredient list rather than the headline
• Plain vitamin C has upset your stomach and you'd like a buffered form
• You train hard and have been told antioxidants will undo your gains. Pooled trials found vitamins C and E didn't
• You'd rather start with food and movement. Exercise raises your antioxidant levels by itself

Check with us first if

• You take warfarin. CoQ10 and ubiquinol must carry a warfarin warning, and resveratrol must carry one naming warfarin and other medicines.
• You're having chemotherapy or radiotherapy. The evidence on antioxidants alongside cancer treatment is limited and unsettled, so your oncology team should make this call, not a shop.
• You're a man looking at high-dose vitamin E. At 400 IU a day in the SELECT trial, prostate cancer rates went up.
• You already take selenium or zinc in a multivitamin. Both have Australian caps, and doubling up is how people go over them.
• You're choosing green tea extract. It contains caffeine, carries a liver warning and interacts with medicines processed by the liver enzyme CYP1A2.
• You take any prescription medicine. Check with your doctor, pharmacist or our naturopaths before starting.

• Ascorbic acid (plain vitamin C). Best known for: The standard form. It's acidic, so doses of a gram or more can upset your stomach. Absorption: The baseline every other vitamin C form is compared against. Typical use: Across 11,306 people, taking it regularly didn't reduce how often ordinary adults caught colds. People under extreme physical stress, like marathon runners and soldiers in subarctic conditions, were the exception.
• Calcium ascorbate, including Ester-C. Best known for: Buffered, non-acidic vitamin C. Absorption: Easier on the stomach than ascorbic acid, with fewer stomach complaints and favourable oxalate changes, across a review of 13 studies. Some studies found higher vitamin C in white blood cells. Typical use: Does the same jobs as plain vitamin C. You'd choose it for comfort, not because it does more.
• Liposomal vitamin C. Best known for: Vitamin C wrapped in a layer of phospholipid (a type of fat). Absorption: One of the alternative forms that gave better blood levels in 7 of 13 studies. That's blood levels, not health outcomes. Typical use: Does the same jobs as plain vitamin C.
• Vitamin E (natural d-alpha or synthetic dl-alpha-tocopheryl acetate). Best known for: The fat-soluble antioxidant vitamin. Absorption: Not compared separately in the evidence we hold. Typical use: The synthetic form at 400 IU a day is the dose used in the SELECT trial, where prostate cancer went up in men, not down. Don't treat high-dose vitamin E as harmless.
• Selenium (selenomethionine, selenite, selenium yeast). Best known for: The trace mineral in the antioxidant mix. Absorption: Not compared separately. There's no evidence to guide a choice between forms. Typical use: Capped at 150 micrograms a day in an Australian listed medicine. Large Cochrane reviews found no cancer or heart benefit, so don't double up on selenium products.
• Beta-carotene. Best known for: The carotenoid your body can turn into vitamin A. Absorption: Not applicable. Typical use: We don't recommend it. Four independent sources link it to more lung cancer and more deaths, mainly in smokers and former smokers.
• Lutein and zeaxanthin. Best known for: The eye carotenoids, and what the AREDS2 study used instead of beta-carotene. Absorption: Not looked at separately in the evidence we hold. Typical use: Eye health formulas. The main case for them is that they're safer than beta-carotene, not that they do more.
• Astaxanthin (from Haematococcus pluvialis algae). Best known for: The red marine carotenoid, taken by mouth only. Absorption: Not looked at separately in the evidence we hold. Typical use: Improved skin moisture and elasticity in pooled trials, but not wrinkle depth. Performance trials used 20 mg or more, which is above Australia's 12 mg cap.
• CoQ10 (ubidecarenone or ubiquinol-10). Best known for: The oxidised and reduced forms of the same compound, sharing one 300 mg daily cap. Absorption: The evidence we hold doesn't support the claim that ubiquinol is absorbed better. Typical use: The strongest heart-related signal of any antioxidant here, from a pooled map of 884 trials rather than one definitive study. Carries a warfarin warning.
• Curcumin (turmeric, Curcuma longa). Best known for: The yellow polyphenol, often sold with piperine or as a phytosome because it's poorly absorbed on its own. Absorption: The evidence we hold has no head-to-head trial of the different delivery formats. Typical use: The largest body of trials in this group for antioxidant markers. Carries a compulsory liver warning.
• Green tea extract (Camellia sinensis). Best known for: Catechins, including EGCG. It comes with caffeine. Absorption: Not looked at separately in the evidence we hold. Typical use: Lowers malondialdehyde (a marker of cell damage) and raises antioxidant capacity. Most products must be taken with food, and total caffeine is capped at 400 mg a day.
• Resveratrol. Best known for: The polyphenol from grape skin, capped at 150 mg a day. Absorption: Not covered by the evidence we hold. Typical use: We found no confirmed benefit on antioxidant measures, and it carries three compulsory warnings, the most of any in this group.
• Glutathione (oral). Best known for: Your body's main home-made antioxidant, taken as a supplement. Absorption: Not covered by the evidence we hold. Typical use: Adults only, and not in pregnancy or breastfeeding. We found no evidence on health outcomes.
• N-acetylcysteine (NAC). Best known for: A building block your body uses to make glutathione. Absorption: Not applicable. Typical use: Not allowed as an oral listed medicine in Australia. Schedule 1 allows it only in skin products at up to 0.001%.

Reference values. There's no recommended intake for antioxidants as a group. The NHMRC links the word to three nutrients. Vitamin C: 45 mg a day for adults, 60 mg in pregnancy and 85 mg when breastfeeding (ages 19 to 50). Vitamin E: an adequate intake of 10 mg a day for men and 7 mg for women. Selenium: 70 micrograms a day for men and 60 for women. Zinc, often sold alongside them, is 14 mg for men and 8 mg for women.

Typical supplemental range. Vitamin C products commonly contain 500 to 1,000 mg, well above the 45 mg recommended intake, and cold trials used at least 200 mg a day. For most of the others, the Australian cap sets the limit rather than a recommended dose: astaxanthin 12 mg a day, CoQ10 and ubiquinol 300 mg combined, resveratrol 150 mg, selenium 150 micrograms and zinc 50 mg.

Upper level. Vitamin C has no upper limit, though the NHMRC calls 1,000 mg a day a sensible limit. Vitamin E's upper limit is 300 mg a day for adults. Selenium's is 400 micrograms from all sources, food included, which is why supplements are capped lower at 150. Zinc's is 40 mg a day for adults, which is lower than the 50 mg a listed medicine may contain. No upper limit can be set for beta-carotene from supplements.

Worth knowing. Some trial doses can't legally be matched here. The original AREDS eye formula used 80 mg of zinc, above the 50 mg cap. Astaxanthin's performance trials used 20 mg or more, above the 12 mg cap. And the 400 IU of vitamin E used in the SELECT trial is a dose where harm was found, not benefit. What you need depends on your age, diet and health, so talk to one of our naturopaths.

Food first, where the diet allows it.

• Cocoa and dark chocolate: lowered a marker of oxidised fat across 33 controlled trials; no per-serve antioxidant figure is available, so none is stated
• Tea: the source of green tea catechins; no per-serve figure is available, so none is stated
• Berries: no per-serve Australian figure is available, so none is stated
• Olive oil: no per-serve Australian figure is available, so none is stated

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

• Smokers and former smokers. Beta-carotene raised lung cancer risk, so don't take it.
• Anyone taking beta-carotene. Pooled trials showed more deaths overall and more deaths from heart disease.
• Men taking high-dose vitamin E. In the SELECT trial, 400 IU a day raised prostate cancer.
• If you take warfarin. CoQ10, ubiquinol and resveratrol carry compulsory warnings.
• Pregnancy and breastfeeding. Resveratrol and glutathione carry compulsory warnings, and caffeine limits apply to green tea.
• Children. Resveratrol isn't suitable, oral glutathione is for adults only, and turmeric isn't allowed under 2, with age-based caps on curcumin.
• Doubling up on selenium. Listed medicines are capped at 150 micrograms a day, and hair loss (alopecia) and skin inflammation (dermatitis) were more common in the SELECT trial.
• Doubling up on zinc. There's a 50 mg cap, a warning above 25 mg, and the adult upper level is 40 mg.
• Liver concerns. Turmeric and green tea carry compulsory liver warnings.
• If you're having cancer treatment. The evidence is limited and unresolved, so check with your oncology team.
• If you take prescription medicines, check with your doctor, pharmacist or one of our naturopaths before you start.