Lutein and zeaxanthin: Eye and vision benefitsより

There currently is no Recommended Dietary Allowance (RDA) or Recommended Daily Intake (RDI) for lutein or zeaxanthin, but some experts say you should ingest at least 6 milligrams (mg) of lutein per day for beneficial effects.

現在までのところ、ルテインとゼアキサンチンのＲＤＡ（推奨許容量）あるいはＲＤＩ（推奨１日摂取量）は設定されていないが、専門家は１日６ｍｇのルテインが効果があると言っている。

It remains unclear how much lutein and zeaxanthin is needed daily for adequate eye and vision protection. Also, it is unknown at this time whether supplements have the same effect as lutein and zeaxanthin obtained through food sources.

眼と視力を守るために必要なルテインとゼアキサンチンの１日必要量は不明であり、サプリメントが食事と同じ効果があるかも不明である。

There are no known toxic side effects of taking too much lutein or zeaxanthin. In some cases, people who eat large amounts of carrots or yellow and green citrus fruits can develop a harmless yellowing of the skin called carotenemia. Though the appearance of the condition can be somewhat alarming and may be confused with jaundice, the yellow discoloration disappears by cutting back on consumption of these carotenoid-rich foods. (Carotenemia also can be associated with over-consumption of carotenoid-rich nutritional supplements.)

ルテインとゼアキサンチンの過量摂取による毒性はこれまで知られていない。ニンジンや黄色あるいは緑色シトラスの過剰摂取はカロチネミアによる皮膚の黄色化をきたすことがある。黄疸と間違えわれることが多少あるが、摂取を中止すれば速やかに改善する。

 

Dose-ranging study of lutein supplementation in persons aged 60 years or older.より

Invest Ophthalmol Vis Sci. 2007 Jan;48(1):17. de Monastario, Francisco

PURPOSE:　目的

To examine the dose-response relationship between oral lutein supplementation and serum lutein concentrations in persons aged 60 years and older, with or without age-related macular degeneration (AMD).

経口ルテインサプリメントの摂取量と血清ルテインの相関を６０歳以上の人々で調べた。（黄斑変性症のある人とない人で）

METHODS:　方法

Forty-five participants with no AMD, large drusen, or advanced AMD, were randomized to receive one of three doses (2.5, 5, or 10 mg) of lutein for 6 months and to be observed for 6 additional months after the cessation of lutein supplementation.

４５人の正常人、大きな色素斑のある者、進行性の黄斑変性症患者に（２．５ｍｇ、５ｍｇ、１０ｍｇ）のルテインを６ヶ月ほど内服継続させ、その後６ヶ月ほど経過観察。

RESULTS:　結果

The mean age of the participants (33 women) was 71 years (range: 60-91). The serum lutein concentrations of each dose group were similar before supplementation, increased at 1 month, and peaked by 3 months. Median serum concentrations of the 2.5-, 5-, and 10-mg groups from baseline to month 6 increased from 18.7 to 35.1 microg/dL (2-fold increase), from 17.8 to 59.2 microg/dL (2.9-fold increase), and from 15.1 to 66.8 microg/dL (4-fold increase), respectively (all P < 0.001). The increases in lutein serum concentrations did not vary with AMD disease severity (P = 0.98). No toxicity was observed with any dose of lutein. No significant changes were detected in visual acuity or visual field tests.

平均年齢は７１歳（６０歳から９１歳、３３人が女性）であった。血清ルテイン濃度は、開始前は変わらなかったが、１ヶ月で上昇し、３ヶ月までにピークに達した。平均濃度はベースラインからそれぞれ（2.5、5、10ｍｇ）、18.7-35.1microg/dl, 17.8-59.2microg/dl, 15.1-66.8microg/dlであった。ルテイン濃度の上昇は、黄斑変性症の重症度と関係しなかった。視力検査等では有意な変化を認めなかった。

CONCLUSIONS:　結論

Increasing doses of lutein supplements significantly increased the serum levels of lutein and zeaxanthin, and doses up to 10 mg were safely administered. A long-term large clinical trial is necessary to investigate the safety and efficacy of lutein in reducing the risk of the development of advanced AMD.

ルテインサプリメントの量を増やすことにより、血清ルテインおよびゼアキアチン濃度を上昇させることができる。１０ｍｇまでは安全に内服できる。　長期にわたる安全性と効果に関する研究が必要である。