High serum lead, cadmium tied to low folate levels

Elevated levels of lead and cadmium in the serum is associated with suppressed concentrations of red blood cell (RBC) folate, reports a recent study.

Drawing from the 2017–2018 cycle of the National Health and Nutrition Examination Survey, the researchers assessed 5,690 adults. Multivariable logistic regression analysis confirmed that serum lead was a significant and negative predictor of RBC folate (β, –18.278, 95 percent confidence interval [CI], –25.835 to –10.721; p<0.001).

Similarly, serum cadmium was strongly tied to lower levels of folate (β, –119.261, 95 percent CI, –210.556 to –27.965; p=0.011). Serum mercury was also found to be an inverse correlate of folate, but its impact did not reach statistical significance (β, –2.745, 95 percent CI, –5.513 to 0.022; p=0.052).

In contrast, serum manganese (β, 4.401, 95 percent CI, 2.416–6.387; p<0.001) and selenium (β, 0.478, 95 percent CI, 0.18–0.776; p=0.002) levels were significantly and positively associated with RBC folate.

Similar patterns were found when participants were grouped according to tertiles of blood metal levels. Those in top vs bottom tertiles of serum lead, for instance, had significantly reduced RBC folate (β, –70.92, 95 percent CI, –94.76 to –47.07; p<0.001). The same was true for serum cadmium (T3 vs T1: β, –39.72, 95 percent CI, –62.69 to –17.16; p=0.001).

“In this study of the US general population, the most remarkable finding was that serum lead and cadmium levels both had an adverse relationship with RBC folate levels. The association became stronger when the highest tertile group was compared with the lowest tertile group,” the researchers said.

“To the best of our knowledge, our research is the first report investigating the relationship between cadmium levels and body folate status,” they added.