PROBLEM TO BE SOLVED: To have an excellent anemia-improving action or anemia-preventing action without strengthening nutritional components (taking high protein or iron), and at least one of the following excellent actions according to (1) to (4). It is an object of the present invention to provide a preparation containing an active ingredient which is a natural product, is highly safe, can be taken as a food, and has high stability. (1) Human red blood cell count maintenance/increasing action, (2) Human blood hematocrit level maintaining/increasing action, (3) Human blood hemoglobin concentration maintaining/increasing action, and (4) Human blood albumin amount Maintenance or increase promotion action. A nucleic acid is used as an active ingredient of an anemia improving agent and/or an anemia preventing agent. [Selection diagram] None【課題】栄養成分の強化（高タンパク質や鉄の服用）なしでも、優れた貧血改善作用または貧血予防作用を有し、更に以下の（１）～（４）にかかる優れた作用の少なくとも１つを有してもよい、天然物系で安全性が高く、食品として摂取でき、安定性の高い有効成分を含む製剤を提供することを目的とする。（１）ヒト赤血球数の維持・増加作用、（２）ヒト血中ヘマトクリット値の維持・増加作用、（３）ヒト血中ヘモグロビン濃度の維持・増加作用、及び（４）ヒト血中アルブミン量の維持または増加促進作用。【解決手段】貧血改善剤および／または貧血予防剤の有効成分として核酸を用いる。【選択図】なし
