Missing out on vital nutrients

Malnutrition is a common issue for people living with inflammatory bowel disease (IBD) and can have significant consequences if left untreated, writes Jessica Chapman.

Couple cooking healthy mealA 2013 systematic review of 84 studies found that malnutrition occurs in both ulcerative colitis (UC) and Crohn’s disease (CD) patients, and has codified both the prevalence and potential complications of various nutritional deficiencies.

The review, published in Clinical Nutrition, noted that “micronutrient depletion continues to affect the majority of IBD patients” and “continues to be clinically relevant, particularly for children”.

The authors conclude that “a complete nutritional assessment and nutritional support… is therefore an important aspect of the treatment of IBD patients, highlighting the importance of multidisciplinary management of individual patients.”

  • Reasons for malnutrition

    There are a range of reasons people with IBD are at high risk of malnutrition including:

    • Reduced oral intake
    • Increased energy requirements (therefore would need to increase calorie intake to meet increased requirements).
    • Poor digestion
    • Malabsorption due to chronic inflammation
    • Previous surgical resection
  • Should I take supplements?

    Before starting any supplements it is important to speak with your healthcare team. Your doctor can arrange blood tests to identify which, if any, nutrients you are deficient in and if necessary can refer you to an Accredited Practising Dietitian for further assistance on achieving a nutritionally adequate diet.

    Where possible, it is best to obtain your nutritional requirements from a balanced diet. While supplements can be useful for certain specific nutritional deficiencies, there is not sufficient evidence to support using supplements in other cases.

    It is essential to speak with your healthcare team before starting any supplements as excess intake of certain nutrients can cause a toxic effect.

  • What's my risk?
    Nutrient at risk of deficiency Prevalence % Reason for deficiency Complications
    UC CD
    Iron 81 39
    • Blood loss
    • Reduced oral intake
    • Abnormal growth
    • Inadequate cognitive development in children and adolescents.
    • Fatigue
    Folate 35 54-67
    • Reduced oral intake for those on low-fibre diets.
    • Medications such as Sulfasalazine and
    • Methotextrate interfere with absorption of folic acid.
    • Weight loss
    • Fatigue and weakness
    • Folate-deficiency anaemia
    • An increased risk of birth defects known as neural tube defects.

    Vitamin B12

    5 48
    • Due to either inflammation, surgery or bacterial overgrowth, the ileum is is unable to absorb Vitamin B12.


    • Fatigue
    • Lack of appetite
    • Weight loss
    • Apathy and depression
    • Anaemia
    Calcium 10 13
    • If there has been resection of the ileum, calcium may bind to unabsorbed fatty acids in the bowel instead of being absorbed.
    • Dairy products are avoided.
    • Osteopenia (weak and fragile bones)
    • Osteoporosis
    Vitamin D 35 75
    • Fat malabsorption
    • Bone and muscle pain
    • Rickets in children
    • Osteopenia (weak and fragile bones)
    Fat soluble vitamins (A, D,E,K) 26-93 11-50
    • Fat malabsorption due to either inflammation or resection of the ileum.
    • Decreased resistance to infections.
    • Dry, rough skin.
    • Increased risk of night blindness.


* Jessica Chapman is an Accredited Practising Dietitian. This article is based on: Massironi S, et al., Nutritional deficiencies in inflammatory bowel disease: Therapeutic approaches, Clinical Nutrition (2013), http://dx.doi.org/10.1016/j.clnu.2013.03.020