. 2020 Sep 1;31(2):682–693. doi: 10.1007/s11695-020-04943-0

Table 2.

Proportion of patients with deficiency in haematinics and haemoglobin and comparison with previous studies

	Baseline	12 months	24 months	36 months	48 months
All patients
Vitamin B₁₂ (%)	7.5	4.4	3.5	1.3	2.3
Folate (%)	4.7	4.9	1.6	4.5	10.3
Serum iron (%)	29.8	15.6	19.3	19.6	27.3
Ferritin (%)	1.1	1.3	4.3	7.1	9.3
Haemoglobin (%)	2.6	4.3	4.7	6.0	7.4
Bypass
Vitamin B₁₂ (%)	8.1 (2.3^a)	5.5 (6.5^a)	4.8 (5.4^a)	1.7 (7.2^a)	3.3
Folate (%)	5.4 (2.2^a)	4.5 (1.6^a)	0.7 (1.8^a)	3.4 (0.7^a)	7.0
Iron (%)	28.7 (14.7^b–15.3^a)	17.0 (10.5^a)	17.5 (9.8^a)	18.6 (10.2^a)	24.7
Ferritin (%)	1.6	1.2	4.4	7.7	10.3
Haemoglobin (%)	1.6 (12.2^a)	3.2 (20.9^a)	5.1 (25.9^a)	5.7 (23.1^a)	6.9
Sleeve
Vitamin B₁₂ (%)	5.8 (5.9^d–9.3^c)	1.5 (7.8^c–17.2^d)	0.0 (1.0^e)	0.0 (18.0^f)	0.00
Folate (%)	2.9 (0.0^c–5.5^d)	5.9 (13.7^c–13.8^d)	4.00	8.1 (22.0^f)	17.50
Serum iron (%)	32.9 (36.6^b)	11.9	24.0	22.9	35.1
Ferritin (%)	0.00	1.47	4.08	0.00	7.14
Haemoglobin (%)	4.9	7.3	3.5	7.0	8.7

Values (comparison with previous studies) reported as percentages (%)

^aWeng et al. [20]

^bEnani et al. [35]

^cAntoniewicz et al. [38]

^dDamms-Machado et al. [32]

^eJavanainen et al. [40]

^fGehrer et al. [37]