Federal regulators granted tentative approval to the first drug for muscular dystrophy, following an intense public campaign from patients and doctors who pushed for the largely unproven medication. The approval came despite an internal dispute among Food and Drug Administration officials that ultimately had to be resolved by the agency's chief. The FDA cleared Sarepta Therapeutics' Exondys 51 for a rare form of Duchenne muscular dystrophy, a deadly inherited disease that affects boys.

Light boosts testosterone in men with low libido

For men whose sex drive has stalled, Italian researchers have found in a small study that early morning exposure to bright light — a treatment widely used for seasonal depression — increases testosterone production and boosts sexual function and satisfaction. Men diagnosed with problems of sexual desire and arousal saw improvements after spending a half-hour each morning for two weeks in front of specially designed light box.

Daily vitamin D may reduce asthma attacks

Daily vitamin D supplements lowered the risk and severity of asthma attacks, according to a review of nine clinical trials. The analysis involved 435 children and 658 adults, most of whom had mild to moderate asthma. The reviewers found that oral vitamin D supplements ranging from 400 to 4,000 units a day reduced the risk of attacks requiring medication by 37 percent. The number of attacks requiring emergency intervention decreased by more than 60 percent among vitamin D users.

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