Vitamin E 500IU

With vitamin E, the doses on the shelf and the doses the evidence supports are often far apart. These are the questions our naturopaths ask in store before anyone buys a bottle.

A good fit if

• A doctor has told you that you absorb fat poorly, because that's where a real vitamin E shortfall shows up
• You eat very few nuts, seeds, vegetable oils or leafy greens, which are where almost all dietary vitamin E comes from
• You want the natural d-alpha form and understand what that means, which is roughly twice the activity per milligram
• You're taking a modest dose as part of a multivitamin rather than a high-dose single capsule
• You'd rather get it from food, which is what the evidence best supports

Check with us first if

• You take warfarin or another blood thinner. Vitamin E works against vitamin K-dependent clotting factors and makes platelets less sticky, and effects have been seen from 300 mg a day, which is less than a single 500 IU capsule.
• You're a man thinking about long-term high-dose vitamin E. The SELECT trial of 34,887 men found 400 IU a day of the synthetic form was linked to a 17 per cent higher relative risk of prostate cancer.
• You have heart disease or diabetes. A seven-year trial in about 9,500 people with these conditions found no heart benefit at 400 IU a day, and higher rates of heart failure and hospital stays for heart failure.
• You take a statin with niacin. Antioxidant combinations including vitamin E were seen to dull the rise in HDL ('good') cholesterol that this treatment aims for.
• You're pregnant or breastfeeding. The Adequate Intake is 7 to 8 mg and 11 to 12 mg a day respectively and the Upper Level is 300 mg, so a high-dose capsule is well outside the range set for you.
• You plan to take it every day for years rather than for a set period, because that's the kind of use the analysis of deaths was measuring.
• If you take prescription medicines, check with your doctor, pharmacist or our naturopaths before starting.

• Natural vitamin E (d-alpha-tocopherol). Best known for: The single stereoisomer your liver's transport protein holds on to most efficiently, extracted from vegetable oil. Absorption: Roughly twice the biological activity of synthetic by weight: 1 mg converts to 1.49 IU, against 2.22 IU for synthetic. Typical use: General supplementation where activity per milligram is what you are paying for. The label reads d-alpha, with no l.
• Synthetic vitamin E (dl-alpha-tocopherol). Best known for: An eight-isomer racemic mixture made industrially, of which only the RRR isomer matches the natural form. Absorption: About half the biological activity of natural, by weight. Typical use: Lower-cost formulations and most multivitamins. This is the form used in the SELECT trial, where 400 IU a day was linked to a 17 per cent rise in prostate cancer risk, so the caution belongs to this form specifically.
• Mixed tocopherols. Best known for: A blend carrying beta, gamma and delta alongside alpha, closer to the way vitamin E turns up in whole food. Absorption: No dedicated human comparison against single-isomer alpha-tocopherol was found for this entry. Typical use: Chosen by people who want the gamma fraction, which neutralises reactive nitrogen species that alpha-tocopherol handles poorly. That evidence is mechanistic and preclinical, not clinical.
• Tocotrienols. Best known for: The other branch of the family, with an unsaturated side chain, sourced from palm, rice bran or annatto. Absorption: A distinct absorption and tissue-distribution pathway from the tocopherols; no head-to-head human comparison was found for this entry. Typical use: Sold as a separate product rather than as a vitamin E substitute. No adequate intake is set for tocotrienols, and the alpha-tocopherol figures do not transfer to them.

Reference values. Australia sets an Adequate Intake rather than an RDI, because the evidence wasn't strong enough to set one. For adults it's 10 mg a day of alpha-tocopherol equivalents for men and 7 mg for women, rising to 7 to 8 mg in pregnancy and 11 to 12 mg while breastfeeding. Children range from 5 mg at one to three years up to 8 to 9 mg at nine to 13.

Typical supplemental range. Australian capsules are commonly sold at 200 to 500 IU, which is 134 to 335 mg, and 1,000 IU products exist. Compared with an Adequate Intake of 7 to 10 mg a day, a single 500 IU capsule is many times a day's dietary need, and it's at or above the 400 IU dose used in the trials that raised safety concerns about vitamin E.

Upper level. The NHMRC sets the Upper Level at 300 mg a day of alpha-tocopherol equivalents for adults, including pregnancy and breastfeeding. It's lower for children: 70 mg at one to three years, 100 mg at four to eight, 180 mg at nine to 13 and 250 mg at 14 to 18. The United States sets its upper level at 1,000 mg, more than three times the Australian figure, so American labels and blog advice aren't a guide here.

Worth knowing. Vitamin E is fat-soluble, so take it with a meal that has some fat in it. The trials that raised concerns about deaths and prostate cancer used 400 IU a day for five to seven years, which is long-term daily use rather than a short course. What you need depends on your age, diet and health, so talk to one of our naturopaths.

Food first, where the diet allows it.

• Wheat germ oil, 1 tablespoon: 20.3 mg, about twice an adult day's adequate intake
• Sunflower seeds, dry roasted, 28 g: 7.4 mg
• Almonds, dry roasted, 28 g: 6.8 mg
• Sunflower oil, 1 tablespoon: 5.6 mg
• Hazelnuts, dry roasted, 28 g: 4.3 mg
• Spinach, boiled, half a cup: 1.9 mg

This list is the part of the page we will not shorten. If any of it applies to you, talk to one of our naturopaths or your doctor before starting.

• Anyone on warfarin or another anticoagulant. Vitamin E antagonises vitamin K-dependent clotting factors and reduces platelet aggregation; bleeding risk rises, with effects noted from 300 mg a day.
• Anyone taking 400 IU a day or more long term. A 19-trial meta-analysis of 135,967 people found a dose-response relationship with all-cause mortality from about 150 IU a day.
• Men considering high-dose synthetic vitamin E. SELECT found a 17 per cent higher relative risk of prostate cancer at 400 IU a day in 34,887 men.
• People with cardiovascular disease or diabetes. HOPE-TOO found no cardiovascular benefit at 400 IU a day and higher heart-failure rates.
• People having chemotherapy or radiotherapy. Antioxidant supplements may reduce treatment effectiveness; oncology agreement is required.
• People on statin plus niacin therapy. Antioxidant combinations including vitamin E blunted the HDL-raising effect.
• Pregnancy and breastfeeding. Adequate intake is 7 to 8 mg and 11 to 12 mg a day; the upper level is 300 mg a day; no TGA advisory was found and no reassurance above the adequate intake is offered here.
• Children. Upper levels are set by age and are far below adult capsule strengths: 70 mg at one to three years, rising to 250 mg at 14 to 18.
• Topical use. Several tocopheryl esters are permitted only on intact skin, not in the eye and not on damaged skin, at capped concentrations.
• People with fat-malabsorption conditions such as Crohn's disease, cystic fibrosis or bile duct obstruction. These are deficiency risks, not excess risks, and dosing should be medically supervised rather than self-managed.
• If you take prescription medicines, check with your doctor, pharmacist or our naturopaths before starting.