Japanese fabric and clothing makers are fiercely competing in the sale of T-shirts and other clothes containing popular dietary supplements.

Nutritive substances including amino acids, vitamins, xylitol and food additives are gaining the spotlight as ingredients in clothing.

People who wear garments containing such supplements are said to be able to maintain the PH balance in their skin or obtain cool comfort after perspiring.

Clothing makers have high expectations for nutritive substances that they believe will become highly promising revenue sources.

But a major department store official said it is difficult to understand the effect of the supplements in clothing.

Major sporting goods maker Mizuno Corp and Ajinomoto Co jointly developed the clothing material "Amino Veil" last year by combing an amino acid into fabric. They put tennis and golf clothes as well as T-shirts made with the fabric on sale in earnest in March.

They used mainly "arginine," made from about 20 kinds of amino acids, because it is said to help regenerate skin.

"It dissolves when someone perspires and enhances the material''''s ability to absorb moisture and helped keep the skin''''s PH level balanced," said a Mizuno public relations department official.

He said Mizuno plans to post 3 billion yen in sales of goods related to Amino Veil five years from now, or about six times the amount projected for the current fiscal year, adding that "sales are going almost according to our plans."

Jeans maker Teijin Wow Co of Osaka is selling "Wow Amino Jean" for women. The jeans incorporate amino acid in the material.

An official of the company said the jeans look no different than other jeans.

But "you get a soft sense when you touch them," the official said. "You don''''t feel the knee parts of the pants thrust out when you ride a bicycle or climb stairs."