母乳餵飼、日光浴不足、偏食等原因令幼児腿骨変形病増加

Recently the Mainichi News on-line reported the following:

くる病:乳幼児に増える　母乳、日光浴不足、食事が要因

毎日新聞　2014年05月02日　11時00分（最終更新　05月02日　13時04分）

　栄養不足の時代に多かった乳幼児の「くる病」が最近、増えている。紫外線対策の普及や母乳栄養の推進などが複合的に関係しているという。専門医は「くる病は母乳で育っている子どもに多く、特に注意してほしい」と呼びかける。

　くる病は、ビタミンＤが極端に不足することで血中のカルシウム濃度が下がり、骨の変形や成長障害などを引き起こす。歩き始める１歳以降、足に負荷がかかってＯ脚になりやすい。

　東京大大学院の北中幸子准教授（小児医学）によると、１９９０年代はほとんどみられなかったが、２０００年ごろから学会報告が目立ち始め、最近は臨床現場で珍しくなくなった。東大病院ではこの１０年ほどで、診断したり他施設からの相談を受けたりしたケースが約１００件に上る。

　ビタミンＤが欠乏している乳幼児の増加の３大要因は、母乳栄養の推進▽日光浴不足▽偏った食事−−という。母乳は赤ちゃんに大切な免疫物質が含まれるなど利点が多いものの、ビタミンＤは人工乳に比べて極めて少ない。また、ビタミンＤは太陽の光にあたると体内で作られるが、皮膚がんやしみ・しわ予防の観点から紫外線対策が普及したことも影響している。

　食物アレルギーでビタミンＤを多く含む卵や魚などを取るのを制限している場合もあり、こうした要因が重なると発症しやすい。

　北中准教授は「世界的にもビタミンＤ欠乏症が増えている。予防策として、特に母乳で育てている子には、日焼けしない程度に日光浴させたり離乳食で魚を取らせたりしてほしい」と話す。

　日本小児内分泌学会は昨年、診断の手引きを作成した。血中ビタミンＤ（２５ＯＨＤ）濃度の測定や膝関節のエックス線画像などで診断するが、２５ＯＨＤの測定は保険適用になっていないなどの課題もある。【下桐実雅子】

(試譯文)

   "Rickets" in infants that happened at a time of malnutrition recently had increased. It was said that the popularity in measures against ultraviolet rays, the promotion of maternal feeding etc. were complexly related. A medical specialist made an appeal by saying that "many rickets happened in children who are fed by mother’s milk, I hope special attention could be paid to that". 

   The calcium concentration in blood dropped because vitamin D ran short seriously, and rickets caused bones to modify and fail to thrive etc. After one year old when walking began, the load applied to the legs could easily turn the feet into bowleg.

   According to Sachiko Kitanaka the Associate Professor (Pediatrics) of the University of Tokyo graduate school, although it was hardly seen in the 1990s, rickets began to be conspicuous in medical society reports from around 2000 and became less rare in these days in clinical practices. In the past ten years in the University of Tokyo hospital, or in consultation in other institutions the number of cases diagnosed went up to about 100.

   The three major factors that had led to an increase in infants’ lacking in vitamin D were: popularity in maternal feeding ▽shortage in sun-bath▽ unbalanced diet.  Although mother's milk had many advantages -- an immunity substance important for a baby was contained -- there was very little vitamin D compared with the synthetic milk. Moreover, vitamin D was made in the body when exposed to sun light, but this was  affected by the popularity in measures against ultraviolet rays with a view to prevent skin cancer or stain and wrinkles.

   With overlapping factors, such as on grounds of food allergy to restrict the eating of eggs and fish etc. which contained much vitamin D, all would make it easy for the symptom to show up.

   Associate Professor Kitanaka said "globally vitamin D deficiency is increasing, especially in children who are raised on mother's milk, the preventive measures would be have more sunbathe to such an extent that one does not get tanned, and to have fish in the baby food".

   Last year the Japanese Society for Pediatric Endocrinology had prepared a guide on diagnosis. Although diagnoses could be made by measuring the vitamin D (25OHD) concentration in blood, and the X ray picture of knee joints etc., whether the measuring of 25OHD was a reliable method had become an issue.

It is surprising to note that maternal feedings could be related to "Rickets" in infants