THURSDAY, Jan. 21 (HealthDay News) -- High levels of vitamin D in the blood appear to be linked to lower risks of colorectal cancer, although it's not clear if higher intake of the vitamin actually prevents the disease, researchers say.

THURSDAY, Jan. 21 (HealthDay News) -- Quitting smoking after a diagnosis of early stage lung cancer doubles the odds that a patient will live another five years, a new study finds.

THURSDAY, Jan. 21 (HealthDay News) -- Fractures, tendonitis and other musculoskeletal and connective tissue injuries are the most common reasons for medical evacuation of U.S. military personnel from Iraq and Afghanistan, a new study shows.

THURSDAY, Jan. 21 (HealthDay News) -- Babies brought to term by healthy, white mothers in the United States now weigh almost 3 ounces less than they did 20 years ago, and no one knows why, a new report shows.

THURSDAY, Jan. 21 (HealthDay News) Smoking, as well as the medicinal use of opioid painkillers such as oxycodone, are independent predictors of longer-term opioid pain medication use among patients with chronic back pain caused by lumbar spine conditions, a new U.S. study finds.

THURSDAY, Jan. 21 (HealthDay News) -- The more overweight you are, the more likely you are to have a stroke, a new study reports.

THURSDAY, Jan. 21 (HealthDay News) -- The weight-loss pill Meridia should not be used by people with a history of heart problems because the drug can increase the risk of heart attack and stroke in such people, U.S. drug regulators said Thursday.

THURSDAY, Jan. 21 (HealthDay News) -- Twenty percent of U.S. children and teens have abnormal lipid levels, an indication of too much bad cholesterol, too little good cholesterol or high triglycerides, federal health officials report.

THURSDAY, Jan. 21 (HealthDay News) -- New technology has made it possible, for the first time, to track the potentially deadly bacteria MRSA around the world or from one person to another, a new study reports.

THURSDAY, Jan. 21 (HealthDay News) -- The ability to detect early-stage ovarian cancer may be improved by using contrast-enhanced ultrasound combined with proteomic analyses of blood samples, a new study shows.

Here are some of the latest health and medical news developments, compiled by the editors of HealthDay:

(HealthDay News) -- Here are the latest clinical trials, courtesy of ClinicalConnection.com:

THURSDAY, Jan. 21 (HealthDay News) -- Researchers report they've developed a test that detects early-stage pancreatic cancer by measuring levels of a protein that's present in 90 percent of cancerous and precancerous lesions.

THURSDAY, Jan. 21 (HealthDay News) -- Chemicals found in carpeting, non-stick cookware and fabrics are linked to an increase in thyroid disease, new research suggests.

THURSDAY, Jan. 21 (HealthDay News) -- The cells of origin for the most common form of breast cancer have been identified by researchers, who say the finding offers a possible new target for breast cancer drugs.

THURSDAY, Jan. 21 (HealthDay News) -- Digital mammography delivers significantly less radiation than conventional mammography, and the reduction in radiation exposure may be greater for women with larger and denser breasts, a new study has found.

THURSDAY, Jan. 21 (HealthDay News) -- For the first time, researchers have been able to diagnose post-traumatic stress disorder (PTSD) by reading patterns of magnetic fields created by brain cells.

THURSDAY, Jan. 21 (HealthDay News) -- A new treatment for a widespread and virulent bacterial infection, Clostridium difficile, appears to dramatically cut recurrence, researchers report.

THURSDAY, Jan. 21 (HealthDay News) -- Scientists say they boosted the success of in vitro fertilization in mice by gently rocking embryos before implanting them into the womb.

(HealthDay News) -- The exact cause of acne isn't understood, but the American Academy of Dermatology says four factors are involved: too much oil, clogged pores, bacteria, and inflammation.

(HealthDay News) -- Repetitive stress injury most often affects people who spend a lot of time at the computer or video game console. The repetitive motions of certain sports, such as tennis, also can lead to an RSI.