Supplements

The malabsorption that occurs in coeliac disease can lead to multiple nutritional deficiencies. The most common nutritional problems in people with coeliac disease include deficiencies of essential fatty acids, iron, vitamin D, vitamin K, calcium, magnesium, folic aid and zinc. For example, serum tests in 26 children with established coeliac disease showed folic acid and iron status were low in 30% of children compared to 14% of controls (1). The prevalence of patients with iron-deficiency who are then found to have coeliac disease is 4.7% (2). Looking at magnesium status, a study on 41 patients showed 20% of coeliacs to have a deficiency (3). This is a concern as magnesium deficiency impairs parathyroid hormone (PTH) secretion and so affects bone turnover and can lead to osteopenia (4).  Supplementing patients with magnesium has been shown to increase PTH secretion and bone mineral density in patients with coeliac disease (4).

Newly diagnosed coeliac patients should be assessed for any nutritional deficiencies; this is normally done by a blood test. If patients are deficient in any vitamins/minerals these will need to be corrected by taking a supplement. Usually, the deficiencies of these nutrients will correct themselves after a gluten-free diet has been started as the body will start to absorb more effectively. For example, a study looked at zinc absorption in newly diagnosed coeliacs and coeliacs who has been on a gluten-free diet for some time. Zinc absorption was low in the newly diagnosed group but absorption had corrected itself in those who had complied with the gluten-free diet (5).

Following a gluten free diet presents a problem with achieving adequate intake of some nutrients.  Gluten-free products compared to their counterparts are often low in B vitamins, calcium, vitamin D, iron, zinc, magnesium, and fibre. Few gluten-free products are enriched or fortified. Research has shown that patients on a gluten free diet have a poor vitamin status. Also if the compliance to the gluten free diet is not good there is a higher chance of deficiencies being present and not correcting themselves. Therefore the patient needs to be under the care of a dietitian and be regularly monitored (7).

Any supplements that are taken should be checked to ensure they are gluten free.

References

1. Haapalahti M et al. Nutritional status in adolescents and young adults with screen-detected celiac disease. J Pediatr Gastroenterol Nutr. 2005;40 (5):566-70. 

2. Patterson R et al. Iron deficiency anaemia: are the British Society of Gastroenterology guidelines being adhered to? Postgraduate Medical Journal 2003;79(930):226-228.

3.  Rujner J et al. Magnesium status in children and adolescents with coeliac disease without malabsorption symptoms. Clin Nutr. 2004;23(5):1074-9.

4. Rude RK, Olerich M. Magnesium deficiency: possible role in osteoporosis associated with gluten-sensitive enteropathy. Osteoporos Int. 1996;6(6):453-61.

5. Crofton RW et al. Zinc absorption in celiac disease and dermatitis herpetiformis: a test of small intestinal function. Am J Clin Nutr 1983; 38:706-12.

6. Hallert C et al. Evidence of poor vitamin status in coeliac patients on a gluten-free diet for 10 years. Alimentary Pharmacology & Therapeutics 2002; 16(7):1333-1339.

7. Kupper C.  Dietary guidelines and implementation for coeliac disease. Gastroenterology. 2005;128(4 Suppl 1):S121