Considering the importance of providing vitamins and minerals in body health, it obviously seems to be necessary to assess the deficiencies of these nutrients in obese patients.

The present study aimed to evaluate the level of hemoglobin, ferritin, and vitamin B12 in a sample of Iranian population with morbid obesity.

This cross-sectional study was conducted on 1252 consecutive patients with morbid obesity referred to obesity clinic at Rasoul-e-Akram hospital from 2009 to 2015 in Tehran, IR Iran. Morbid obesity was defined as body mass index (BMI) equal to or higher than 40 kg/m². Serum hemoglobin level (gr/dL) was measured using the cyan methemoglobin method. Serum ferritin level (ng/mL) can be measured by the human ferritin enzyme immunoassay test. Also, serum vitamin B12 concentration (pg/mL) was measured using the solid-phase, competitive chemiluminescent enzyme immunoassay method.

Overall, 1252 patients with morbid obesity were included in the study. The mean age of participants was 39.77 ± 10.84 years (ranged 10 to 70 years) and 80.3% of them were female. The mean body weight was 126.75 ± 21.58 kg and the mean BMI was also 46.99 ± 5.87 kg/m². In result, 9.8% were anemic according to the low value of hemoglobin level, 46.6% had ferritin lower than the normal range and the average serum level of vitamin B12 was lower than the normal value in 21.1%. By applying the Pearson’s correlation test, a positive association was found between BMI value and the level of hemoglobin (r = 0.074, P = 0.009).

Morbid obesity may result in two important hematologic and metabolic changes including increased hemoglobin level and reduced vitamin B12 level. Since, vitamin B12 has vital role in the body, providing adequate vitamin B12 is essential in these patients even by using vitamin supplements. Also, regular screening of the level of hematologic markers in these patients is strongly recommended.