Table 4.

Results of elastic net regression models assessing the associations between all maternal or paternal toenail metal concentrations (separate parental models) or all parental toenail metals (combined parental model) with spina bifida status, using regression coefficients extracted for when lambda equals lambda min (n=278).

	Penalized Coefficient (Beta)

	Separate Parental Models		Combined Parental Model

	Maternal	Paternal	Maternal	Paternal
Aluminum (Al)^a	0.000	0.000	0.000	0.000
Arsenic (As)^a	0.000	0.154	0.000	0.112
Cadmium (Cd)^a	0.000	0.000	0.000	0.000
Cobalt (Co)^a	0.000	0.000	0.000	0.000
Chromium (Cr)^a	0.000	0.120	0.000	0.112
Copper (Cu)^a	−0.037	0.000	−0.065	0.000
Iron (Fe)^a	0.000	0.148	0.000	0.119
Mercury (Hg)^a	0.000	0.000	0.000	0.000
Manganese (Mn)^a	0.000	0.000	0.000	0.000
Molybdenum (Mo)^a	0.000	0.000	0.000	0.000
Nickel (Ni)^a	0.000	0.000	0.000	0.000
Lead (Pb)^a	0.000	0.000	0.000	0.000
Antimony (Sb)^a	0.000	0.000	0.000	0.000
Selenium (Se)^a	0.150	0.469	0.000	0.404
Tin (Sn)^a	0.000	0.000	0.000	0.000
Uranium (U)^a	0.000	0.000	0.000	0.000
Vanadium (V)^a	0.000	0.000	0.000	0.000
Zinc (Zn)^a	−0.261	−0.068	−0.222	0.000
Maternal Serum Folate (ng/mL)^b	0.000	0.000	0.000	-
Birth Place, home birth	0.000	0.000	0.000	-
Mom Age (years)	0.000	0.000	0.000	-
Dad Age (years)	0.000	0.003	-	0.000
Child Sex, male	−0.119	−0.180	−0.118	-

Note: All estimates are from elastic net regression models adjusting for maternal age (years), paternal age (years), infant sex, place of birth, and maternal serum folate (ng/mL, natural log transformed).

Toenail metal concentrations (in μg/g) were natural log transformed and scaled prior to analysis.

Maternal serum folate was natural log transformed prior to analysis.