Table 1.

Immune implications of micronutrient deficiencies in IBD.

Micronutrient	Level in IBD	Purported Pathogenic Role of Deficiency
Vitamin A	↓ [27]	↓ TREG cell differentiation [18,19,20,21] ↑ TH17 cell differentiation [20] ↓ T cell migration into the gut [25]
Folate	↓ [43]	↓ TREG cell survival [31,32] ↑ Proinflammatory signaling [37,39] ↑ Oxidative stress [37,38]
Vitamin B12	=↓ in patients with ileal resection [54]	--
Vitamin D	↓ [61]	↑ T cell activation [56] ↑ Proinflammatory signaling [56] ↓ Decreased T cell turnover [57]
Calcium	↓ [87,90,91]	--
Vitamin K	↓ [62]	↑ Proinflammatory signaling [84,85]
Iron	↓ [104]	--
Zinc	↓ [8,118]	↑ Proinflammatory signaling [114] ↑ Oxidative stress [116,117]
Selenium	↓ [134,135,136,137,138,139]	↑ Proinflammatory signaling [141] ↑ Oxidative stress [130]

This table presents the immune implications of micronutrient deficiencies in adult IBD patients. The arrows describe the effect of IBD on the level of micronutrient present in the individual, as well as the effect on the purported pathogenic role related to that micronutrient. For example, ↑ indicates an increase, ↓ indicates a decrease, and =↓indicates about the same or less.