On Nutrition by Ed Blonz

AVOIDING POISON IVY RASH AND 'NIACIN FLUSH'

DEAR DR. BLONZ: Is there any dietary supplement that can help one avoid the misery of poison ivy/oak/sumac? I had heard a vitamin or herb could help, but I would even be open to a prescription medication. Are you aware of anything you can take? -- C.B., via email

DEAR C.B.: I wish it was otherwise, but there are no vitamins or herbs that have been shown to bolster the body's defenses against those peksy poison plants. The rash that develops is a true allergic reaction to the oil called urushiol (oo-ROO-she-awl) found in these plants.

The best defense is avoidance, or some sort of barrier -- be it clothing (that gets carefully handled and double-washed in hot water afterward) or a cream that prevents the oil from coming in contact with your skin. Two commercial products to try are the barrier cream IvyBlock and the cleanup wash Tecnu. These work well for many. Under the "avoidance" banner, remember that pets can be complicit in spreading urushiol around. Cats and dogs often walk in and around the troublesome greenery, and then have little compunction in sharing what they have brushed against.

If you have already been in contact with one of these plants, there are a number of anti-itch products available to help minimize the misery. Contact your physician if you have a nasty case, as there are also prescription medications that can help.

I happen to be one of those unfortunate souls who is hypersensitive to those plants -- just typing this response is making me itch. Parkland surrounds my house, and it is teeming with poison oak. Despite my best efforts, every season I seem to come down with a case of that itchy menace. If there were any vitamin or herb that worked, I would be all over it (and it would be all over me).

DEAR DR. BLONZ: Can niacin be harmful to one's health? I get some pretty bad rashes when I take niacin, and it seems like an allergic reaction. What do you say? -- N.L., Tucson, Arizona

DEAR N.L.: It is doubtful that you are allergic to niacin, which is an essential nutrient. The daily value for niacin on food labels is 20 milligrams per day. What you are probably experiencing is a "niacin flush," which is nothing more than a dilation of the small blood vessels near the skin. This can occur when a higher dose of the nutrient is taken, usually about 10 times the daily value. It varies from person to person; some can experience a flush at much lower doses.

A flush can be avoided by lowering your intake of niacin, taking it in divided doses or shifting to a "flush-free" form of niacin such as nicotinamide or inositol hexanicotinate.

Niacin -- also known as vitamin B3, or the related compounds nicotinic acid and nicotinamide -- is required for normal cell metabolism and energy release from carbohydrates. Niacin also plays a role in the synthesis of hormones and DNA. Food sources include organ meats, poultry, seafood, nuts, green vegetables and legumes. Some individuals take high levels of niacin to treat elevated cholesterol, but that may be less effective than was once thought. Read an update at tinyurl.com/nsa7ymn.

Send questions to: "On Nutrition," Ed Blonz, c/o Universal Uclick, 1130 Walnut St., Kansas City, MO, 64106. Send email inquiries to questions@blonz.com. Due to the volume of mail, personal replies cannot be provided.