Objective To evaluate the relationship between nutrients intake in the first trimester of pregnancy and blood levels of lead and cadmium during the first and third trimesters of gestation. Methods A total of 381 pregnant women were enrolled. Blood lead and cadmium were measured using electrothermal atomic absorption spectrometry, and dietary intake was assessed using 24‐h recall questionnaire. Results Lead levels in the first trimester were negatively correlated with cadmium levels in the two trimesters, and levels of both metals correlated positively in the third trimester. Zinc and calcium intakes were negatively associated with blood lead during third trimester. Thiamine and folic acid intakes were negatively and positively associated (respectively) with blood lead at third trimester with marginal significance. Fat, niacin, and vitamin B12 intakes were significantly and positively associated with blood cadmium at first trimester. Folic acid and zinc intakes showed positive and marginally significant associations with blood cadmium without adjustments. At third trimester, blood cadmium was negatively associated to ascorbic acid intake, and positively associated with iron intake with a marginal significance. Conclusions Possible acute and late effects of nutrients intake in blood lead and cadmium levels could be related with associations exclusively observed in the first and third trimester. This study represents the first exploration of relationships among a wide range of nutrients intake in the first trimester of pregnancy with blood lead and cadmium in first and third trimester of gestation. Further studies are required to confirm the findings mentioned herein. Am. J. Hum. Biol. 25:344–350, 2013. © 2013 Wiley Periodicals, Inc.