Relationship between vitamin B 12, iron, folic acid, homocystein and vitamin D 3serum levels in orofacial sicca and/or Sjögren's syndrome in a Hungarian patient population

Abstract

Introduction: Vitamins D3-and B12, folic acid and/or iron deficiency might cause orofacial sicca symptoms: dry mouth, migrant glossitis, burning mouth, and further associated orofacial symptoms including mucosal atrophy or inflammation. Vitamin deficiencies, on the other hand, might expand the xerostomia-related unpleasant conditions. Little is known about the serum levels of the above-mentioned laboratory parameters, and about the level of homocysteine in patients with orofacial sicca symptoms and/or Sjögren s syndrome. It is known that patients with autoimmune diseases have a declined level of vitamin D3 and it is in correlation with the disease activity in systemic lupus erythematosus and in rheumatoid arthritis. Moreover, oesophageal and gastric mucosal alterations associated to orofacial sicca symptoms might cause systemic symptoms and influence nutrition and digestion of the patients. Objective: This study evaluated the difference of serum levels of vitamins D3 and B12, folic acid, homocysteine, furthermore the levels of iron, transferrin and transferrin saturation between Hungarian healthy individuals and patients with dry mouth and/or Sjögren s syndrome. Method: Participants were divided into 4 groups according to their existing subjective (xerostomia, xerophthalmia - assessed by a structured questionnaire) and objective (hyposalivation assessed by sialometry) sicca symptoms and/or definitive diagnosis (assessed by the ACR-EULAR diagnostic system) of Sjögren s syndrome as follows: 1. healthy controls, 2. xerostomia, 3. hyposalivation, and 4. Sjögren s syndrome groups. Results showed that in Sjögren s syndrome (group 4) serum vitamin D3 and iron level, whereas, in the hyposalivation (group 3) only the serum iron level was significantly decreased, compared to the healthy controls (iron: group 1: 36.24 ± 20.14 ng/ml, group 2: 47.85 ± 26.84 ng/ml, group 3: 42.04 ± 21.03 ng/ml, group 4: 26.96 ± 7.53 ng/ml; p 0.05); vitamin D3: group 1: 36.24 ± 20.14 ng/ml, group 2: 47.85 ± 26.84 ng/ml, group 3: 42.04 ± 21.03 ng/ml, group 4: 26.96 ± 7.53 ng/ml, p 0.05). Vitamin B12, transferrin and transferrin saturation, folic acid and homocysteine levels did not show difference in any groups compared to the healthy controls. Discussion and conclusion: Serum level of vitamin D might be associated with the autoimmune inflammation in Sjögren s syndrome, and the decreased value of serum iron might rather be accompanied by the health state of the oral and gastroesophageal mucosa due to absorption or nutritional problems. The above could be explained by the association we found between the serum iron - but not vitamin D3 - level and the reduced unstimulated whole saliva flow rate.