Serum folate and vitamin B12 levels in patients with small cell lung cancer.

Serum folate and vitamin B12 levels were evaluated in 80 patients with small cell lung cancer at diagnosis and during therapy over a 30-week period. Approximately one half of the patients were randomized to receive hyperalimentation. Folate and vitamin B12 intake was adequate without parenteral nutrition in these cancer patients. Serum folate and Vitamin B12 levels did not correlate with disease extent. At the initiation of therapy, serum folate declined with increasing weight loss. During therapy, the intake of folate was adequate to maintain a normal serum folate despite marked weight loss.