CHECKUP : NEWS, TIPS AND TRENDS TB NEEDN'T ADD TO FEARS OF FLYING.

Frequent fliers can breathe a little easier. Although tuberculosis can be transmitted on long airplane flights, the risk of infection is low, a new report shows.

In the study of 802 people who flew with a TB-infected passenger on one of four flights, 13 of 14 people who tested positive for TB after two of the flights had other risk factors for the disease.

And while six of 15 passengers who tested positive for TB after sharing the longest flight - about nine hours - with the passenger had no risk factors, all six had been seated in the same section of the plane as the infected passenger, the researchers reported in the New England Journal of Medicine.

As of February 1996, all six infected passengers were symptom-free, researchers noted.

``The decision to notify passengers and crew members potentially exposed to tuberculosis should be guided by ... the flight duration, the infectiousness of the patient and seating proximity,'' concluded researchers, led by Dr. Thomas A. Kenyon of the Centers for Disease Control and Prevention in Atlanta.

The new study was prompted by a panic set off when a woman with rampant TB traveled extensively in 1994. Tuberculosis, a lung infection caused by Mycobacterium tuberculosis bacteria, infects one-third of the world's population and is responsible for 3 million deaths each year, according to the CDC.

Drink your milk: Pregnant women who consume the recommended amount of calcium are less likely to develop high blood pressure and its complications during pregnancy, compared with women who do not, a new study shows.

In the analysis of nearly 2,500 women, those who took about 1,500 milligrams to 2,000 milligrams of calcium a day during pregnancy were 70 percent less likely to have pregnancy-induced hypertension than those who did not take supplements.

And women who took calcium supplements were two-thirds less likely than the other women to develop preeclampsia, a potentially deadly hypertension-related disorder of late pregnancy, Canadian researchers reported Wednesday in the Journal of the American Medical Association.

Pregnancy-induced hypertension is one of the leading causes of death in pregnant women, and a major cause of complications in women and their fetuses. Calcium is thought to prevent high blood pressure by widening blood vessels.

The National Institutes of Health currently recommends that pregnant women consume 1,200 milligrams to 1,500 milligrams of calcium a day.

Heavy issue: Yet another health problem has been linked to being overweight: An obese woman who becomes pregnant is more likely than her leaner counterparts to give birth to a baby with one of the most common birth defects in the United States - a malformation of the brain or spine known as a neural-tube defect - according to two new studies.

And even though taking folic acid before and during pregnancy reduces the risk of neural-tube defects (NTDs), that may not be true for obese women, according to the reports, published in the Journal of the American Medical Association.

Folic acid is a B vitamin found naturally in leafy vegetables such as spinach and broccoli. The vitamin is so important in preventing NTDs that the U.S. Public Health Service recommends that all women of childbearing age consume 400 micrograms of folic acid a day to reduce the risk of the defects.