Pietrzik K, Urban G, Hötzel D
Int J Vitam Nutr Res. 1978;48(4):397-401.
Criteria to judge the folate supply have been evaluated in previous studies. The present study is examining parameters to estimate the degree of folate deficiency. Serum folate levels and erythrocyte folate concentrations were measured in 116 volunteers (patients). The erythrocyte folate is to a large extend independent of exterior supply and is lowered only in severe chronic deficiency. Low levels of erythrocyte folate indicate longstanding undersupply. Our experiments show that folate concentration of greater than 250 ng per ml erythrocytes indicate adequate supply. Concentrations below this limit are characteristic for chronic folate deficiency. To confirm this statement further studies will take into account the urine concentration of formiminoglutamic acid.
以往的研究已对判断叶酸供应的标准进行了评估。本研究正在检测用于估计叶酸缺乏程度的参数。对116名志愿者（患者）测定了血清叶酸水平和红细胞叶酸浓度。红细胞叶酸在很大程度上独立于外部供应，仅在严重慢性缺乏时才会降低。红细胞叶酸水平低表明长期供应不足。我们的实验表明，红细胞叶酸浓度大于每毫升250纳克表明供应充足。低于此限值的浓度是慢性叶酸缺乏的特征。为进一步证实这一说法，后续研究将考虑尿中亚胺甲基谷氨酸的浓度。
