Folate status of adult males living in a metabolic unit: possible relationships with iron nutriture.

Folate and iron status was monitored at monthly intervals in 40 adult males who were living in a metabolic unit for 2 to 8 months and consuming diets containing 150 to 250 micrograms of folate per day. There were significant (p less than 0.02) declines in hematocrit, serum folate, and serum ferritin. Men who participated in studies for 6 months or more or those with initial serum folate levels more than 10.5 ng/ml and erythrocyte folate levels more than 481 ng/ml also exhibited a highly significant (p less than 0.001) decline in red blood cell folate. Men with erythrocyte folate below 480 ng/ml or serum folate below 10 ng/ml and who participated in the studies for less than 5 months showed little or no change in folate status. The findings may reflect adjustments in body folate to reflect dietary intakes. Also a folate intake of 200 +/- 68 micrograms/day appeared to be adequate for maintenance of folate stores in adult males. A correlation between iron stores and folate status was also observed. However, this relationship may be coincidental.