"...all doctors should be able to diagnose and treat nutritional deficiencies."

Royal College of Physicians. Nutrition and Patients: A Doctor's Responsibility. London 2002


This page has been printed from the www.stewartnutrition.co.uk web site.


Despite public enthusiasm for the use of nutritional supplements in those undergoing cancer treatment there is still no clear documented advantage of their use.  Some patients with more advanced or aggressive cancers may develop nutritional deficiencies during the course of their illness and require nutrition support.  However agents used in chemotherapy treatment may have anti-nutrient effects and the co-administration of nutritional supplements may thus be unwise as they might blunt the effects of medication in curbing the growth of the cancer itself.

Additionally some nutrients are potentially growth-promoting and this could apply to vitamin A, beta-carotene (which is converted into vitamin A), zinc and possibly some of the B vitamins.  The rapidly dividing cancer cells may have a bigger appetite for these and other nutrients than your own healthy tissues.  The Cochrane Review - Antioxidant Supplements for Prevention of Mortality in Healthy Participants and Patients with Various Diseases (April 2008) found that vitamin A, beta-carotene and vitamin E appeared to increase the risk of both cancer and an early death [internal link].  Thus a cautious approach seems reasonable until more definitive advice is available.

Some Sensible Advice

  • Check with your oncologist/medical advisor before taking any nutritional supplements before or during chemotherapy or radiotherapy.
  • Some agents such as methotrexate act by inhibiting the action of folate and supplements of it should not be taken at the same time without medical advice and this will include most multivitamins and supplements of vitamin B complex.
  • If nutritional deficiencies are present or develop during treatment they should be dealt with, where possible, by dietary means and supplements should only be considered for clinically significant proven deficiencies.
  • If nutritional supplements are to be given it may be prudent to not administer them on the same day that chemotherapeutic agents are also being taken.
  • It should be remembered that most if not all of the trials of chemotherapeutic agents from which your doctors are selecting the best treatment for you almost certainly did not include using nutritional supplements and thus their addition to your regime is adding an unknown variable for which at present there is no substantial justification.
  • On completion of treatment if the cancer has gone into remission this may be a better opportunity to make some use of nutritional supplements depending upon clinical need

For further advice see www.bacup.co.uk and Cancer Research Campaign and BUPA website


Copyright Dr. Alan Stewart M.B.B.S.M.R.C.P. (UK)M.F. Hom.
47 Priory Street, Lewes, East Sussex. BN7 1HJ
Tel 01273 487003 Fax: 01273 487576