Vitamin D has little effect in preventing seniors from dying of cancer or heart disease, a British study found.
"A supplement or vitamin might not have the magic bullet to prevent the next disease," Peggy Cawthon of the California Pacific Medical Center Research Institute told Reuters Health. "We've had a lot of examples, and vitamin D is just the latest showing it has no effect on these health issues."
Earlier studies linked low vitamin D levels in the blood to a greater risk of death from heart problems, and researchers hypothesized that Vitamin D supplements might prove effective in cutting the risk. But Dr. Alison Avenell, lead study author at the University of Aberdeen, said the data is weak.
Avenell's team tracked nearly 5,300 people over age 70 who were vulnerable to bone fractures, dividing them into four groups who took pills for two to five years, and followed up with three years later.
One took 800 IU (International Units) of vitamin D daily, another group took 1000 milligrams of calcium each day, and the third group took both. A fourth group received placebos. Thirty-two out of every 100 people who took Vitamin D died during the study, while 33 out of every 100 people not taking Vitamin D died. The calcium pills showed similar results.
"People often stopped taking their tablets, so we might not have had enough people taking tablets to find effects," Avenell wrote in an email to Reuters Health, and said she looks forward to studies demonstrating further effects of Vitamin D supplements. "The dose of vitamin D might not have been high enough."
The study appeared in the journal Clinical Endocrinology and Metabolism.
