No significant association was found between the consumption of dietary calcium, magnesium, or zinc and the risk for ulcerative colitis (UC), according to results from a systematic review and meta-analysis published in Clinical Nutrition ESPEN.
Researchers from the Shahid Beheshti University of Medical Sciences in Iran searched publication databases through September 2021 for observational studies about UC and consumption of micronutrients. Of 5705 electronic records identified, 7 studies met the inclusion criteria.
Six of the studies were of case-control designs and 1 was a cross-sectional study. The studies were published between 2014 and 2021 and were conducted in Iran, Jordan, Croatia, Italy, and Poland.
The study population comprised 1197 participants, 388 of whom were cases and 809 control individuals. One study recruited only men.
Dietary calcium had no significant association with UC (n=1205; weighted mean difference [WMD], -66.25; 95% CI, -276.7 to 144.21 mg/day; P =.54; I2=95.1%). However, in studies conducted in non-Asian countries, decreased calcium intake increased risk for UC (WMD, -201; 95% CI, -284.1 to -117.89 mg/day; P <.001; I2=0%).
Similarly, dietary magnesium did not associate with UC risk (WMD, -21.47; 95% CI, -95.54 to 52.6 mg/day; P =.57; I2=96%). But, in studies with fewer than 190 participants, higher magnesium intake increased risk for UC (WMD, 30.29; 95% CI, 8.83-51.75 mg/day; P =.03; I2=0%).
For zinc, no relationship was observed (WMD, 0.3; 95% CI, -1.5 to 2 mg/day; P =.74; I2=95.8%).
A sensitivity analysis using a leave-one-out approach found similar outcomes.
The study may have been biased by not performing gender-specific subgroup analyses.
The study authors concluded, “All in all, based on the results of this study, no significant association was found between dietary intake of calcium, magnesium, and zinc and the risk of UC. Further studies with higher power are therefore warranted to investigate the relationship and effects of micronutrients such as calcium, magnesium and zinc in the context of UC.”
Salavatizadeh M, Soltanieh S, Chegini M, et al. Micronutrient intake and risk of ulcerative colitis: a meta-analysis of observational studies. Clin Nutr ESPEN. Published online July 18, 2022. doi:10.1016/j.clnesp.2022.07.008