Vitamin E (alpha-tocopherol)

Ranges vary between laboratories (for example 12 to 42 or 11.6 to 46.4 umol/L), and because the vitamin travels with blood fats many labs also print a vitamin E to cholesterol ratio, with a lower limit of around 2.2 umol per mmol.

Vitamin E, measured as alpha-tocopherol, is a fat-soluble vitamin that protects cell membranes from damage. It is carried in the blood inside the same particles that carry cholesterol, so the level rises and falls with blood fats. Shortage is rare on an ordinary diet and nearly always comes from a problem absorbing fat.

It is requested when fat is poorly absorbed, for example in cystic fibrosis, pancreatic disease, cholestatic liver disease, Crohn's disease or after weight-loss surgery, in some inherited conditions, and when unexplained nerve or balance problems are being looked into. It is on some private nutrition panels.

• Vitamin E supplements
• High cholesterol and triglycerides, which carry more of it
• Pregnancy and oestrogen-containing contraception, slightly
• Long-term intravenous feeding with lipid

• Poor absorption of fat: cystic fibrosis, pancreatic disease, cholestatic liver disease, coeliac disease, Crohn's disease, weight-loss surgery
• Low cholesterol, which lowers the total without lowering what is available
• Very rare inherited conditions of fat transport
• Premature birth, in babies
• Prolonged very low-fat diets

• It tracks blood fats, so a low cholesterol gives a low vitamin E and a high cholesterol a high one, which is why the ratio to cholesterol is printed
• A non-fasting sample after a fatty meal reads higher
• The sample has to be protected from light

A fasting morning sample, protected from light, often with cholesterol measured at the same time so the ratio can be worked out.

Written by a UK consultant physician. Typical UK adult reference ranges; your laboratory's own printed range takes precedence.