Ranitidine Side Effects & Health Impacts

Zinc depletion compromises innate and adaptive immune responses, leading to lymphopenia, reduced T-cell function and higher susceptibility to infections.

Classic dermatology and immunology literature shows that zinc deficiency causes lymphopenia and reduced immune capacity; more recent work links marginal deficiency to impaired inflammatory and anti-microbial responses.

Fraker PJ et al. The dynamic link between the integrity of the immune system and zinc status. JAMA Dermatol. 1987;123(2):169-174.; Lopez EA et al. Systematic review and meta-analysis of the effect of zinc on wound healing. Nutr Clin Pract. 2025;40(2):123-135.

Low zinc disrupts keratinocyte proliferation, collagen synthesis and epithelial repair, resulting in delayed wound healing, dermatitis and poor tissue regeneration.

Experimental and clinical studies demonstrate that zinc deficiency is associated with skin lesions, delayed wound closure and abnormal inflammatory responses, while zinc repletion can improve healing outcomes in selected populations.

Lin PH, Sermersheim M et al. Zinc in wound healing modulation. Nutrients. 2017;9(1):16.; News-Medical. The role of zinc in immune health and wound healing. 2024.; Lopez EA et al. Systematic review and meta-analysis of the effect of zinc on wound healing. Nutr Clin Pract. 2025;40(2):123-135.

Folate depletion impairs one-carbon metabolism, leading to elevated homocysteine, endothelial dysfunction and potential promotion of atherothrombotic events.

Meta-analyses of randomized trials show that folic acid supplementation lowers homocysteine and modestly reduces stroke and overall cardiovascular disease risk in some populations, especially where baseline folate status is low, highlighting the adverse vascular profile of folate deficiency.

Li Y et al. Folic acid supplementation and the risk of cardiovascular diseases: a meta-analysis of randomized controlled trials. J Am Heart Assoc. 2016;5(8):e003768.; Wang Y et al. The effect of folic acid in patients with cardiovascular disease: a meta-analysis. Medicine (Baltimore). 2019;98(38):e17106.; Miller ER et al. Meta-analysis of folic acid supplementation trials on risk of cardiovascular disease. Am J Cardiol. 2010;106(4):517-527.

Folate deficiency impairs DNA synthesis, resulting in ineffective erythropoiesis, macrocytosis and megaloblastic anemia, often accompanied by glossitis, mucosal changes and fatigue.

Hematology and nutrition reviews describe folate deficiency as a classic cause of megaloblastic anemia and mucosal abnormalities, frequently exacerbated by medications that antagonize folate metabolism.

O’Leary F, Samman S. Vitamin B12 in health and disease. Nutrients. 2010;2(3):299-316. (discussion of folate and B12 in megaloblastic anemia); Lešić S et al. The impact of vitamin deficiencies on oral manifestations. Dent J (Basel). 2024;12(4):109.

B12 depletion impairs DNA synthesis in rapidly dividing cells, leading to macrocytic (megaloblastic) anemia, fatigue, pallor and, in severe cases, pancytopenia.

Clinical reviews identify vitamin B12 deficiency as a common cause of megaloblastic anemia; hematologic abnormalities often improve with replacement, underscoring the hematopoietic consequences of depletion.

Langan RC, Zawistoski KJ. Update on vitamin B12 deficiency. Am Fam Physician. 2017;96(6):384-389.; Green R. Vitamin B12 deficiency from the perspective of a practicing hematologist. Blood. 2017;129(19):2603-2611.

Sustained B12 deficiency damages myelin in the peripheral and central nervous system, resulting in paresthesias, gait disturbance, impaired proprioception and cognitive or mood changes.

Systematic reviews and observational data show associations between low B12 levels and peripheral neuropathy, myelopathy and cognitive impairment; neurological manifestations may become irreversible if depletion is prolonged.

Badar A et al. Neuropsychiatric disorders associated with vitamin B12 deficiency: an updated review. Cureus. 2022;14(2):e22052.; Dekker MJHJ et al. Vitamin B12 deficiency-induced neuropathy and cognitive impairment. J Nutr Gerontol Geriatr. 2024;43(1):1-15.; NHS. Vitamin B12 or folate deficiency anaemia – complications. 2017.

Vitamin A depletion impairs regeneration of rhodopsin in the retina and maintenance of ocular surface epithelium, causing night blindness, dry conjunctiva, Bitot spots and, in severe cases, corneal ulceration and blindness.

WHO and ophthalmology literature identify vitamin A deficiency as a leading cause of preventable childhood blindness worldwide, with graded ocular signs (night blindness, conjunctival xerosis, Bitot spots, corneal involvement) used to monitor population deficiency.

Gilbert C. The eye signs of vitamin A deficiency. Community Eye Health. 2013;26(84):66-67.; World Health Organization. Xerophthalmia and night blindness for the assessment of vitamin A deficiency. WHO/NMH/NHD/EPG/14.4. 2014.; DeMaeyer EM. The WHO programme of prevention and control of vitamin A deficiency. Nutr Rev. 1986;44(9):285-294.