The Personalised Supplement Revolution — Does Your Body Actually Need Any of This

Personalised supplement companies are testing your blood and shipping custom vitamin packs. Here is what the science actually says about whether you need them — and what most people actually lack.

The personalised supplement market — companies that test your blood, analyse genetic data, or assess your dietary logs to generate personalised vitamin and supplement recommendations shipped to your door in labelled daily packets — is one of the fastest-growing segments of the wellness market. Brands including Persona Nutrition, Baze, Supplement Spot, and Thriva have built businesses on the premise that supplement needs vary enough between individuals that personalisation provides meaningfully better outcomes than general supplementation guidance.

The science on where individual variation in supplement needs is real and consequential: vitamin D status varies enormously by latitude, sun exposure, skin pigmentation, and genetic variants affecting vitamin D metabolism. Approximately 40 percent of US adults have vitamin D levels classified as insufficient by the Endocrine Society's threshold. Iron deficiency, particularly in menstruating women, affects approximately 20 percent of women of reproductive age in developed countries despite most not knowing it. Omega-3 fatty acid status varies with seafood consumption and genetic variants affecting conversion efficiency.

In these categories — vitamin D, iron, omega-3 — blood testing genuinely identifies deficiencies that targeted supplementation can address, and the personalised supplement companies' blood testing component provides real clinical value.

The categories where personalised supplementation adds less value than its pricing implies: most B vitamins, most antioxidants, most botanical extracts whose blood levels either aren't measured or whose supplementation benefits don't depend on baseline status. For the general healthy adult without documented deficiency, the research on most common supplement categories shows little to no benefit compared to adequate dietary intake from whole foods.

For the consumer making the purchase decision: a one-time comprehensive blood test (vitamin D, iron studies, B12, omega-3 index, homocysteine, magnesium, zinc) is less expensive than most personalised supplement subscription services and provides the actual baseline information on which evidence-based supplementation can be rationally targeted. Supplementing what you're actually deficient in is more cost-effective than subscribing to a personalised pack of things you might or might not need.