Supplements that make a difference after 40 — and the ones that don't

Roberto is 52, an engineer, measures everything. He came to the office with a bag — literally, a pharmacy bag — containing seventeen bottles. Resveratrol, NMN, glutathione tablets, generic multivitamin, B-complex, liposomal vitamin C, type II collagen, curcumin without piperine, spirulina, maca, two “longevity formulas” labeled in English. Doctor, I spend a fortune a month. But I don't know if any of this is doing anything.

I asked for the recent labs. Vitamin D at 22 ng/mL — below the sufficiency range. Serum magnesium 1.7 mg/dL — at the floor of the “normal” range, which says little because serum magnesium underestimates tissue deficiency. Omega-3 index (which he had ordered on his own) at 4.2% — below 8%, the cardiovascular risk band. Creatine, he had never taken — I thought it was just for the gym.

Roberto is the common case. It is not a lack of care. It is disorganized excess.

The pyramid of what has evidence

The supplementation literature for healthy adults over 40 is vast — and most of it is weak: small studies, surrogate endpoints, homogeneous populations, conflicts of interest. When filtered by randomized trials of reasonable size, with clinically relevant endpoints, the list of what survives is short. Creatine monohydrate. Omega-3 (EPA+DHA, or pure EPA at high dose for specific indications). Vitamin D in the deficient. Magnesium in the deficient or in specific conditions. That is the hard core.

Everything else — NMN, NR, resveratrol, oral glutathione, curcumin without a vehicle, generic multivitamin, collagen powder, mega-dose antioxidants — either has weak evidence, or neutral evidence, or evidence against. It is not malice to say this. It is reading the literature.

Creatine — the most underestimated

Creatine monohydrate is probably the supplement with the best evidence-to-price ratio ever studied. It was stigmatized for decades as “gym stuff” and is being rediscovered in the longevity clinic for the right reason.

The Chilibeck and colleagues meta-analysis, published in 2017 in the Open Access Journal of Sports Medicine, aggregated 22 randomized trials in adults aged 57 to 70 on average. The creatine + strength training group gained on average 1.37 kg (3 lbs) more lean mass than the placebo + training group, with significant gains in bench press and leg press strength. The effect happens with 3 to 5 g/day, no loading phase, no cycling. There is no signal of kidney harm in people with normal renal function — a repeated concern that the specific literature does not support.

More recently: data suggest additional benefit in cognition and mood in older adults, especially during periods of sleep deprivation or stress. Muscle is the body's largest creatine store, but the brain also uses it — and the passage across the blood-brain barrier explains the neurocognitive effect.

Practical indication: 3–5 g/day of creatine monohydrate (not exotic forms — micronized or standard monohydrate). Taken consistently, every day, with or without training.

Omega-3 — the story is more nuanced

The omega-3 story is less clear than it appears on social media. The VITAL trial, published by JoAnn Manson and colleagues in 2019 in the NEJM, randomized more than 25,000 adults to 1 g/day of fish oil or placebo, with five-year follow-up. There was no statistically significant reduction in the composite primary cardiovascular endpoint. For the general population, with no specific indication, 1 g/day of generic fish oil does not prevent heart attack.

But the picture changes with indication. REDUCE-IT, conducted by Deepak Bhatt and also published in 2019 in the NEJM, randomized 8,179 patients with elevated triglycerides (150–499 mg/dL) already on statin to receive icosapent ethyl (pure EPA, high dose — 4 g/day) or placebo. A 25% reduction in major cardiovascular events. Dose, purity, and indication matter.

The Yang Hu, Frank Hu, and Manson meta-analysis, published in the Journal of the American Heart Association in 2019, aggregating 13 trials and 127,000 participants, confirmed a modest but significant reduction in cardiovascular mortality with marine omega-3 supplementation, with a more consistent effect in EPA formulations than in low-dose mixed EPA+DHA formulas.

Practical indication: the Omega-3 Index test (erythrocyte) tells you where you stand. Target: above 8%. For most people who eat fatty fish (sardine, salmon, tuna) two or three times a week, the index is already in adequate range. For others, supplement combined EPA+DHA around 2 g/day, with a certified formulation (IFOS seal or equivalent). In patients with elevated triglycerides and cardiovascular disease, the discussion is with a cardiologist — higher dose, pure EPA, individual decision.

Vitamin D — only worth measuring

Vitamin D became an emblematic case of overpromise. VITAL also tested 2,000 IU/day of vitamin D3 against placebo. No reduction in total cancer or cardiovascular events in the general population. A modest, late signal for cancer mortality, but the primary endpoint was not met.

The honest reading of the data: vitamin D supplemented blindly, without prior measurement, in an adult without deficiency, prevents nothing. In people with 25-OH-vitamin D below 30 ng/mL — common in Brazil among those who work indoors — replacement makes sense for bone health, possibly for muscle and immune function. Reasonable target band: 40 to 60 ng/mL. Typical doses to reach that band vary widely — 1,000 to 4,000 IU/day in most cases — and the definition is with blood, not by guess. Co-administering with vitamin K2 (MK-7 form) is common in clinical practice to minimize vascular calcium deposition, although the evidence here is still weaker.

Magnesium — the silent one

Magnesium is the opposite case: subclinical deficiency is probably the most common in developed countries. The DiNicolantonio and colleagues review in Open Heart (BMJ) in 2018 synthesized the problem well: average intake in Western populations is below the RDA (310–420 mg/day), serum magnesium only falls after tissue stores are already depleted, and deficiency is associated with hypertension, insulin resistance, arrhythmias, migraines, and poor sleep quality.

Practical indication: typical replacement dose 200–400 mg/day of elemental magnesium, in absorbable forms — glycinate (best for sleep and anxiety), citrate (laxative effect if you overdo it), threonate (crosses the blood-brain barrier, emerging cognition data). Avoid magnesium oxide — poor bioavailability.

What does not pass the filter

• NMN, NR, resveratrol: evidence in humans is still weak. Studies show increased serum NAD+, but consistent clinical endpoints have not arrived. Expensive. Wait.
• Oral glutathione: poorly absorbed in the digestive tract. N-acetylcysteine (NAC) has better evidence as a precursor.
• Generic multivitamin: large studies have not shown benefit in well-nourished adults. May be useful in elderly with restricted intake.
• Collagen powder: modest data for joints and skin, but inferior to simply hitting the daily protein target.
• Curcumin without piperine or lipid vehicle: bioavailability close to zero.
• Mega-dose antioxidants (vitamin C 5 g, vitamin E 1,000 IU): may attenuate training strength gains, paradoxically.

The reading the Continuum makes

Continuum Plenya does not sell supplements, has no store counter, has no affiliation. The supplementation list is designed based on specific labs — Omega-3 Index, 25-OH-vitamin D, magnesium (serum and sometimes intracellular), ferritin, B12, homocysteine. The recommendation is nominal: the substance, the dose, the trustworthy brand, the reassessment interval. Roberto, from the beginning, today takes four things. For the first time, I know why for each one.

A supplement is not a healthy-life vitamin. It is medication without a prescribing label — and medication without indication is a problem waiting to happen.