Fig. 2.

Haematinic levels during 4 years of follow-up after bariatric surgery categorized by sex and type of surgery: a vitamin B₁₂ levels, b proportions of patients with sufficient (black) or low (< 211 ng/L; grey) vitamin B₁₂ levels, c serum folate levels, and d proportions of patients with sufficient (black) or low (< 4.0 μg/L; grey) serum folate levels. In line graphs, points (± error bars) represent means (± standard errors of the means). At each timepoint, fractions depict number of participants contributing data (numerator) over total number of eligible participants (denominator). In column charts, the first column at each timepoint represents all patients, second men, third women, fourth gastric bypass, and fifth sleeve gastrectomy