For years now, a link between vitamin C and mood has been gaining traction in the field of nutritional research. A 2002 study in the journal Biological Psychiatry, for example, found that high doses of ascorbic acid (vitamin C) were associated with improved mood and increased sexual activity in about 80 healthy young adults.
Now a study from the Jewish General Hospital in Montreal finds that acute-care patients given daily doses of vitamin C for about a week experienced rapid improvements in mood. A control group given daily vitamin D did not show any of the same effects. (More on Time.com: The ‘Other’ Salt: 5 Foods Rich in Potassium)
It’s impossible to say whether the same mood-boosting effect would be seen in healthy people, however. Acute-care patients are characterized by severe deficiencies in both vitamins C and D.
“About one in five acute-care patients in our hospital have vitamin C levels so low as to be compatible with scurvy,” Dr. L. John Hoffer, an investigator in the study and a professor of medicine at McGill University, said in a statement. “But patients are rarely given vitamin supplements. Most physicians are simply unaware of the problem. Subclinical deficiencies of vitamin C and D have each been linked to psychological abnormalities, so we examined that aspect in our clinical trial.” (More on Time.com: Why Can’t Americans Eat Their Fruits and Veggies?)
Bottom line: if you’re healthy and getting sufficient levels of vitamins from your diet, an extra glass of morning OJ probably isn’t going to make you any more chipper than usual.