Doctors behind three new studies and an editorial on the question of whether daily multivitamins make us healthier say: no, they don't. After reviewing available evidence and conducting new trials, one set of authors wrote, "We believe that the case is closed — supplementing the diet of well-nourished adults with (most) mineral or vitamin supplements has no clear benefit and might even be harmful."
Their editorial summarizing the new research was published this week in the Annals of Internal Medicine. "These vitamins should not be used for chronic disease prevention. Enough is enough." [CBS News]
Your mileage may vary, and consult your doctor for medical advice in your own situation.
Assuming this new research (which you should read in full) is foolproof, this still doesn't mean that specific supplements for specific people at specific times aren't helpful, or even medically important.
A personal aside: During my cancer treatment, I learned that my vitamin D levels were extremely low, and my oncologist says this is correlated with higher risk for breast cancer incidence and recurrence in women.
Does low D cause cancer? Either "no," or they don't know.
Is a higher D level associated with longer disease-free life in women? Yes.
Do I supplement with D3 every day, eat D-rich foods, get daily sunlight, and have my blood levels checked every few months? You bet your ass I do.