Always tired or struggling to stay motivated? That can sound an awful lot like chronic fatigue. New research points to a blood marker that may help explain why — and it’s one already linked to heart and brain health.

Belly fat becomes increasingly common as we age. But researchers have discovered something that could make it far more dangerous: having too little of one important vitamin at the same time.

Vitamin C has a reputation for boosting the immune system and supporting skin aging. But brain scans reveal a much bigger role: one tied to gray matter, brain connections and cognitive aging. Keeping your levels up may be easier than you think…

Think summer sunshine is enough to rebuild your vitamin D stores? New research suggests that for many people the “sunshine vitamin” may stay low all year long. And that could matter more with every passing birthday.

Most people expect pain after surgery. But one common vitamin deficiency could make that pain worse — leaving patients in need of more opioid medication to get through recovery. That’s not surprising once you know this vitamin’s pain-relieving links…

After years of mixed findings, a new meta-analysis may explain why vitamin D helps depression symptoms in some studies but not others: Like with medicine, dosage matters…