Supplemental information.

"Vitamin E Loses Luster: Nutrient tests show disappointing results" (SN: 3/19/05, p. 182) is the fourth time I've seen a report that vitamin E may not be appropriate for elderly people at cardiac risk. Detailed statistics are always given, but one fact is always omitted: what type of vitamin E was used in the study. Failing to explain what form of vitamin E was used makes the report incomplete and suspect.

ROGER A. RIEHM, ELMORE, OHIO

In this study, did they use both tocotrienols and tocopherols, including alpha, beta, gamma, and delta versions of vitamin E, the only proper version of the vitamin? How much vitamin E did they use per day?

JOHAN RUNEBERG, HELSINKI, FINLAND

The last time I looked, the recommended daily allowance (RDA) for vitamin E was only 30 international units, but typical supplement pills had 200 or 400 international units. There is a lot of room in between. Because RDAs are based on avoiding obvious deficiencies rather than on the subtler concepts of overall risks and benefits, there is a good chance that taking more than the RDA is beneficial while taking hugely more than the RDA is not.

BARRY K. ROSEN, STORMVILLE, N.Y.

The daily dose in the study was 400 international units of alpha-tocopherol vitamin E, the form most active in people. Some scientists hypothesize that alphatocopherol could lessen the effect of the other tocopherols.--N.SEPPA

Another possible reason for the disappointing results for vitamin E is suggested by the writings of Adele Davis years ago. She pointed out that nutrients fall into balance groups. Ingesting too much of one item in the group tends to produce a deficiency of other members of the group. Three such groups are the B vitamins, the three minerals calcium, phosphorus, and magnesium, and the two minerals sodium and potassium. Perhaps the fat-soluble vitamins A, D, E, and K act as a group in this way. Then, taking too much vitamin E by itself might produce a deficiency of the others.

ROBERT COTTON, MARLBORO, N.Y.