When Maria, 78, reaches for her morning vitamins, she's likely grabbing at least a handful of pills—and many of them may be doing nothing at all. The supplement industry markets these products with sweeping promises of boosted energy, stronger immunity and sharper brains, creating the impression that a well-stocked medicine cabinet is the gateway to healthy ageing. But for older adults, the real question isn't whether supplements are universally "good" or "bad"—it's whether someone is actually deficient and whether a supplement is the safest way to address it.
Nutritional deficiencies do become genuinely more common with age. Appetite naturally decreases, oral health often worsens, and chronic illnesses multiply. Many older people take medications that interfere with how the body absorbs, uses or clears nutrients. Dental problems—tooth loss, gum disease, poorly fitting dentures—can make chewing difficult and shrink dietary variety. Well-meaning advice to eat less, lose weight and stick to soft foods can leave someone subsisting on small meals, soups and tea that fill the stomach without meeting real nutritional needs. In this context, targeted supplementation based on confirmed deficiency makes sense. Untargeted supplementation for people already eating adequately often wastes money and sometimes causes harm.
Vitamin B12 is one of the clearest cases. Deficiency becomes more common with age because the stomach produces less acid needed to release B12 from food. Low levels can cause anaemia, fatigue, nerve problems, numbness, tingling, and sometimes memory problems or confusion. Certain common medications—metformin for diabetes and proton pump inhibitors for acid reflux—increase the risk further. High-dose oral B12 often works well, though some people need injections.
Folate matters for red blood cell formation and DNA production, and low levels can raise homocysteine, a blood marker linked to cardiovascular disease and cognitive decline. But folate may only help selected groups: people with confirmed low folate or B12 status, raised homocysteine, or mild cognitive impairment. Critically, B12 deficiency must be ruled out first, because folate can improve certain blood signs of B12 deficiency while nerve damage continues unchecked.
Vitamin D warrants supplementation when levels are low and sun exposure is limited—particularly for people with osteoporosis, recurrent falls or high fracture risk. Yet a large trial found that vitamin D supplementation did not significantly reduce fracture risk in generally healthy older adults who weren't selected for deficiency. More is not automatically better.
Calcium and magnesium support bone, muscle and nerve function, but should come from food whenever possible. Magnesium is widely promoted for sleep, but evidence for routine use as an insomnia treatment remains limited. Multivitamins can help older adults who eat very little or have poor dietary variety, but a large study of three US cohorts found that daily multivitamin use was not associated with lower risk of death.
One of the most overlooked "supplements" isn't a vitamin at all: protein. Many older adults eat too little, yet expert groups recommend around 1.0 to 1.2 grams per kilogram of body weight daily for healthy older people. Low intake contributes to sarcopenia—age-related muscle loss—which increases risk of falls, frailty and lost independence. Sometimes protein intake matters more than any pill in the cabinet.