点击显示 收起
Council for Responsible Nutrition
1828 L Street, NW, Suite 900
Washington, DC 20036
USDA HNRC on Aging Tufts University
711 Washington Street
Boston, MA 02111-1574
USDA HNRC on Aging
Tufts University
711 Washington Street
Boston, MA 02111-1574
PO Box 456
Rosemount, MN 55068
Linus Pauling Institute
Oregon State University
571 Weniger Hall
Corvallis, OR 97331
Department of Nutrition
Arizona State University
7001 East Williams Field Road
Mesa, AZ 85212
Task Force SIGHT AND LIFE
PO Box 2116
4002 Basel
Switzerland
Department of Pathology
LSU Health Sciences Center
533 Bolivar Street, Room 748
New Orleans, LA 70112
Department of Molecular Pharmacology and Toxicology
USC School of Pharmacy
1985 Zonal Avenue
Los Angeles, CA 90089-9121
E-mail: jhathcock{at}crnusa.org
Dear Sir:
Two significant issues were raised by Hemilä—that our review (1) focused only on mortality as a measure of safety, and that substantial evidence indicates an increase in respiratory infections among some population groups at vitamin E intakes in the range of 50-200 mg/d.
Notwithstanding Hemilä's interpretation, our review did not focus on mortality alone as a safety outcome; rather, the sentence he quotes is taken from our section on specific studies dealing with this single aspect of safety. Our conclusions were based on clinical trials that individually evaluated the effects of vitamin E on ischemic heart disease, cancer, type 2 diabetes, Alzheimer disease, Parkinson's disease, or age-related macular degeneration. All of these trials included standard monitoring for potential adverse effects as assessed by standard clinical chemistries, hematologic indicators, and clinical examination. Our review noted the presence or absence of any indications of adverse effects.
With regard to the effect of vitamin E on risk of infection, we note that, although the trial of Graat et al (2) involved a large cohort and a 2 x 2 factorial treatment design, we consider the health assessment by self-evaluation to be a limiting factor. In contrast, we consider the professional evaluation in the trials by Meydani et al (3, 4) to be much more reliable and to justify greater confidence in the possibility that supplementation with 200 IU vitamin E/d protects against upper respiratory tract infections, particularly the common cold, in elderly nursing home residents (4). Other differences in dosage and subjects may have contributed to the different outcomes in the studies by Graat et al (2) and Meydani et al (4).
Our review was intended to be a safety evaluation based exclusively on clinical trial data. We did not encourage large-dose vitamin E self-supplementation in the ordinary population, only the apparent relative safety of vitamin E up to 1600 IU/d (equivalent to 1073 mg RRR- -tocopherol). What is more important, we did state (in agreement with Hemilä), "The UL is not intended to apply to the most sensitive persons in sensitive subpopulations... but, instead, to apply to the healthy general population...." We did not review, and our conclusions do not assume, a homogenous population.
ACKNOWLEDGMENTS
JNH is employed by a vitamin and dietary supplement trade association. AD is a consultant to a dietary supplement trade association and other associations. KK is employed by a vitamin manufacturer. None of the other authors had any personal or financial conflicts of interest.
REFERENCES