Carusos 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 form (stereoisomer) your liver's transport protein holds on to best, extracted from vegetable oil. Absorption: Roughly twice the activity in the body of synthetic, by weight: 1 mg equals 1.49 IU, against 2.22 IU for synthetic. Typical use: General supplementing where you want the most activity per milligram. The label says d-alpha, with no l.
• Synthetic vitamin E (dl-alpha-tocopherol). Best known for: A mixture of eight forms (isomers) made in a factory, and only one of them, RRR, matches the natural form. Absorption: About half the activity in the body of natural, by weight. Typical use: Many formulas 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 applies to this form specifically.
• Mixed tocopherols. Best known for: A blend with beta, gamma and delta forms alongside alpha, closer to how vitamin E occurs in whole food. Absorption: We found no dedicated human comparison against alpha-tocopherol alone. Typical use: Chosen by people who want the gamma form, which neutralises reactive nitrogen compounds that alpha-tocopherol deals with poorly. That evidence comes from lab and mechanism studies, not clinical trials.
• Tocotrienols. Best known for: The other branch of the family, with a different side chain, sourced from palm, rice bran or annatto. Absorption: Absorbed and spread through the body differently from the tocopherols; we found no direct human comparison. Typical use: Sold as a separate product rather than a vitamin E substitute. There's no adequate intake set for tocotrienols, and the alpha-tocopherol figures don't carry over 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

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

• If you take warfarin or another blood thinner. Vitamin E works against vitamin K-dependent clotting factors and reduces how platelets clump together, so bleeding risk rises, with effects seen from 300 mg a day.
• Taking 400 IU a day or more long term. A 19-trial meta-analysis of 135,967 people found the risk of death from any cause rose with dose from about 150 IU a day.
• Men thinking about high-dose synthetic vitamin E. The SELECT trial found a 17 per cent higher relative risk of prostate cancer at 400 IU a day in 34,887 men.
• Heart disease or diabetes. The HOPE-TOO trial found no heart benefit at 400 IU a day, and higher rates of heart failure.
• Chemotherapy or radiotherapy. Antioxidant supplements may reduce how well treatment works, so your oncology team must agree first.
• Statin plus niacin treatment. Antioxidant combinations including vitamin E blunted the rise in HDL cholesterol.
• Pregnancy and breastfeeding. The adequate intake is 7 to 8 mg and 11 to 12 mg a day, and the upper level is 300 mg a day. We found no TGA advisory, and we can't reassure you about taking more than the adequate intake.
• 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.
• Use on the skin. Several tocopheryl esters are allowed only on unbroken skin, not in the eye and not on damaged skin, at capped strengths.
• Conditions that affect fat absorption, such as Crohn's disease, cystic fibrosis or a blocked bile duct. These raise the risk of deficiency, not excess, and dosing should be supervised by your doctor rather than managed yourself.
• If you take prescription medicines, check with your doctor, pharmacist or our naturopaths before you start.