Table 2.

Regression models for breast milk secretory immunoglobulin A (ln transformed, n = 202)^a

	Model 1				Model 2				Model 3a				Model 3b
Predictors	Coef.	SE	P	β	Coef.	SE	P	β	Coef.	SE	P	β	Coef.	SE	P	β
Maternal nutrition
Maternal IDA	−0.06	0.06	0.30	−0.07	−0.05	0.06	0.37	−0.06	−0.05	0.06	0.35	−0.06	−0.05	0.06	0.36	−0.06
Maternal VAD	−0.07	0.06	0.23	−0.08	−0.07	0.06	0.24	−0.07	−0.08	0.06	0.20	−0.08	−0.1	0.06	0.08	−0.11
Maternal MUACb	0.02	0.01	0.06	0.12	0.02	0.01	0.03	0.13	0.02	0.01	0.05	0.12	−0.01	0.01	0.49	−0.06
Infant characteristics
Infant ageb					0.00	0.00	0.05	0.13	0.00	0.00	0.33	0.07	0.00	0.00	0.03	0.14
Infant sex (male)					−0.05	0.04	0.26	−0.07	−0.05	0.04	0.21	−0.08	−0.05	0.04	0.28	−0.06
Mother–infant interaction
VAD×infant age									0.00	0.00	0.02	0.16
MUAC×infant sex													0.05	0.02	0.00	0.26
Adjustment variables
Milk total protein	1.06	0.14	0.00	0.05	1.12	0.14	0.00	0.53	1.12	0.14	0.00	0.53	1.13	0.14	0.00	0.53
Community
Karare	Ref				Ref				Ref				Ref
Korr	−0.02	0.07	0.7	−0.02	−0.01	0.07	0.88	−0.01	−0.02	0.07	0.77	−0.02	0.01	0.06	0.93	0.01
Kituruni	0.15	0.06	0.01	0.17	0.15	0.06	0.01	0.18	0.14	0.06	0.01	0.16	0.15	0.06	0.01	0.17
Constant	6.21	0.14	0.00	–	6.16	0.14	0.00	–	6.17	0.14	0.00	–	6.16	0.14	0.00	–

β, standardized regression coefficient.

^aFor respective model, R²: 0.27, 0.29, 0.30 and 0.31. Adjusted R2: 0.24, 0.26, 0.27 and 0.28. Mean VIF: 1.09, 1.10, 1.13 and 1.11.

^bCentered values used for MUAC and infant age.

IDA, iron deficiency anemia; VAD, vitamin A deficiency; MUAC, mid-upper arm circumference.