Serum Micronutrient and Micromineral Concentrations and Ratios in Healthy Omani Subjects

Objective: This study aimed to establish reference ranges of serum concentrations of copper, zinc, retinol, α-tocopherol, copper:caeruloplasmin and copper:zinc ratios in a group of healthy Omani men and women. Materials and Methods: Assay techniques employed were atomic absorption spectrophotometry (copper and zinc), reverse-phase high-pressure liquid chromatography with isocratic elution (retinol and α-tocopherol), immunonephelometry (caeruloplasmin) and spectrophotometry (albumin and cholesterol). Results: The mean ± SD (μM) obtained for copper, zinc, retinol, and α-tocopherol were 15.9 ± 3.0, 14.2 ± 2.0, 1.45 ± 0.39 and 16.9 ± 4.4, respectively. The mean ± SD for copper:zinc and copper:caeruloplasmin ratios were 1.15 ± 0.30 μmol/mmol and 6.99 ± 0.84 μmol/g, respectively. Significantly higher (p 0.0001) copper and caeruloplasmin concentrations, copper:zinc and copper:caeruloplasmin ratios and lower zinc, retinol, α-tocopherol, cholesterol concentrations and α-tocopherol:cholesterol ratio were present in women compared to men. Age appeared to be associated with copper and retinol concentrations, and copper:caeruloplasmin ratios in women; in men, the association was mostly moderate with caeruloplasmin, α-tocopherol, cholesterol concentrations and α-tocopherol:cholesterol ratios. Smokers had decreased albumin (p = 0.002), zinc (p = 0.023) concentrations, and copper:caeruloplasmin ratios (p = 0.002), increased α-tocopherol concentrations (p = 0.016) and α-tocopherol:cholesterol ratios (p = 0.021) compared with non-smokers. Deficiency incidence was ≤5% for all investigated parameters. Conclusions: Reference ranges of micronutrient concentrations and micromineral ratios were established for Omani subjects. The mean values of several micronutrients were lower than those reported for other populations and some showed gender effects.