9 Supplements an Immunologist Relies On for Healthy Aging

The Immunologist’s Daily Supplement Routine for Aging Well

After two decades researching the immune system, 44-year-old immunologist and health coach Dr. Jenna Macciochi has built a personal supplement routine that’s as deliberate as it is dense. She takes nine different products every day — a regimen that would cost more than £200 a month to copy.

Because she develops supplement formulas and fine-tunes doses for a living, people constantly ask her the same two questions: Which supplements actually matter? And, what do you take?

Her answer starts with a caveat. She won’t endorse anything without solid scientific backing and sees supplements as fitting into two main categories.

• One group fixes deficiencies — like vitamin D, which many people are told to take from October through March, when sunlight (our main source) is scarce.

• The second aims to “optimize” health and longevity — a much more controversial area, where quality can be inconsistent, side effects possible and products sometimes used as a crutch for poor lifestyle habits.

“The foundations of health are all the boring things that are really hard to do consistently: diet, lifestyle, sleep and stress management,” says Dr. Macciochi, author of Immune to Age: The Game-Changing Science of Immune Health. Only once those four pillars are in place does she believe supplements can genuinely enhance overall health.

She admits she’s more experimental than the average person — it comes with the territory. But after a recent deep-dive assessment of her body (including blood, stool and urine tests), every marker came back in the optimal range. “So I’m doing something right,” she says.

Every morning, she keeps her supplement stash in a box by the kettle and takes them with breakfast. Here’s what she uses, and why.

Vitamin D3 and K2: For Immunity and Frailty Prevention

“In the winter I take vitamin D3 and K2,” she explains.

Vitamin D is essential for bone, teeth and immune health. The D3 form is the same one the body produces when skin is exposed to sunlight, and it’s commonly sold as tablets, drops or sprays. It’s often paired with vitamin K2.

“Vitamin K2 helps to make sure the D3 is absorbed into bones and teeth,” she says. Together, the two may help maintain stronger bones, reduce frailty risk and support immune function.

According to Dr. Macciochi, many people are significantly low in vitamin D by the end of the holiday season if they haven’t been supplementing. “They’ll get an awful cold in January and February,” she notes. “We can do a lot for our immune system over winter just by taking vitamin D, and it’s a cheap supplement to add in.”

She prefers a liquid version that she sprays under her tongue.

Magnesium: For Muscles, Nerves and Better Sleep

Magnesium is involved in converting food into energy and is essential for proper muscle, nerve and bone function. It’s also linked to sleep quality — healthy levels have been associated with longer, more restful sleep and less fatigue.

While magnesium is found in leafy greens, legumes, whole grains, nuts and seeds, intake surveys suggest many people still don’t get enough. “Research shows that levels of magnesium in our soil are so much lower than 50 years ago,” Dr. Macciochi says. “So, even if we’re eating a really good diet, most of us are not getting the amount of magnesium that we need.

“Add to that the fact that modern-day stress uses up more of our magnesium reserves and we’re more likely to be deficient.”

Magnesium comes in several forms:

• Magnesium citrate (bound to citric acid)

• Magnesium glycinate (bound to glycine)

• Magnesium oxide (bound to oxygen and salt)

Dr. Macciochi helped create a supplement that blends magnesium malate, taurate and glycinate, designed to support muscles and recovery. “I take this supplement at night to help me sleep,” she says. She avoids magnesium citrate because she finds it harsher on the gut and more likely to have a laxative effect.

Omega-3 and Omega-7: For Brain, Heart and Skin

Omega-3 fatty acids, abundant in fish, nuts and seeds, have long been linked to heart and brain health, reduced inflammation and slower biological aging.

“Most people in the UK are not getting the right amount of omega-3 in their diet, so it’s worth taking an omega-3 supplement,” she says.

Her own choice is a supplement that also contains omega-7. The body can produce this fatty acid, but levels naturally drop with age. “Omega-7 is very good for the skin and mucosal barriers of our body, so that can be very useful for ageing,” she explains.

Creatine and Taurine: The Midlife “Energy Duo”

Creatine and taurine may be best known in gym culture, but Dr. Macciochi believes they’re relevant for many people in midlife, not just athletes.

“Energy is a perennial health issue for people,” she says. “Everyone wants more.”

Creatine helps replenish phosphocreatine stores, increasing the energy available to cells. “We know about creatine’s benefits for athletes and performance because muscles are energy-intensive cells, but the brain, the immune system and many other parts of our body use creatine as well,” she notes.

Taurine, an amino acid and antioxidant found in shellfish and meat, becomes more important as we age. “It helps with cellular energy,” she says. “Together with creatine, it’s a nice duo.”

She buys both as powders and mixes them into yogurt at breakfast. She believes this combo has boosted her workout stamina and improved recovery afterward.

Collagen: Beyond Skin Deep

“Collagen has this reputation for [improving] women’s skin, but really it helps with things like exercise recovery and minimising injuries because it is the protein that makes up most of our bodies,” Dr. Macciochi says.

Collagen production drops with age. Supplements can’t stop this decline entirely, but they aim to slow it down so that skin, joints and other collagen-dependent tissues stay more resilient for longer.

“It’s not just about our looks and skin appearance – I’ve found the whole-body effects to be quite profound,” she says.

She takes powdered collagen and encourages people to check labels for sustainable sourcing. She stirs her dose into yogurt rather than using ready-made liquid collagen drinks, which often contain additives like potassium sorbate to prevent mold and bacteria growth.\

Probiotics and Postbiotics: Guarding the Gut Barrier

“Research is emerging about the gut barrier being key to overall health as we age,” she says. This barrier is incredibly thin — just one cell layer — and separates the contents of the gut from the rest of the body.

“The gut barrier really takes a hit in modern life,” she explains. Diets low in fiber, exposure to microplastics, pesticides and various additives in ultra-processed foods all contribute to what she describes as a heavy inflammatory burden.

To help counter this, she takes both a probiotic and a postbiotic. Probiotics introduce beneficial microbes, while postbiotics (non-living microbial components) are thought to support barrier repair and reduce inflammation.

“Looking after the gut barrier can also change things like how your clothes fit [as they reduce bloating], the regularity of bowel movements and leave you with more energy,” she says. She uses powdered forms and mixes them into soups or stews at lunch or dinner.

Ergothioneine: A “Wild Card” for Brain Health and Longevity

“Ergothioneine is an antioxidant that protects us from oxidative stress,” Dr. Macciochi explains. The body cannot make it on its own, and while foods like mushrooms and organ meats contain it, most modern diets are relatively low in it.

“We know from some of the emerging research that it’s linked with brain health, longevity and healthspan,” she says. “It’s a bit of a wild card, and the research is quite young, but I was convinced enough to start taking it.”

CoQ10: An Underused Longevity Tool

“There are so many longevity supplements around now and, while I’m not convinced by most of them, CoQ10 seems to be beneficial,” she says.

Coenzyme Q10 (CoQ10) is an antioxidant present throughout the body. Its job is to neutralize free radicals — unstable molecules that can damage cells, interfere with DNA and accelerate aging.

People taking statins may have particular reason to consider CoQ10, since those medications can lower the body’s natural levels. Existing research also suggests CoQ10 can significantly reduce the risk of heart attacks and strokes in patients with heart failure.

“We have decades of data showing it’s potentially really useful for longevity,” she notes. “I think it’s an underutilised longevity supplement.” She takes it as a capsule each morning.

Spermidine, Quercetin and Fisetin: Targeting “Inflammaging”

The three newest additions to her regimen are spermidine, quercetin and fisetin. “These are the three I’ve most recently added to my supplement stack,” she says.

All three are plant-derived compounds that may help combat “inflammaging” — the low-level, chronic inflammation that accumulates as we get older.

Spermidine appears to support autophagy, the body’s cellular clean-up and recycling system, helping clear out damaged “zombie cells” associated with aging. It’s thought to benefit the brain and heart over time.

Quercetin is a flavanol found in plants and has been linked with reduced frailty. Fisetin, another plant compound, is also believed to help remove senescent (zombie) cells.

She takes a single pill that combines all three. “Although the research is really new,” she says, “I was convinced by the science behind these supplements, compared to some of the others that you see advertised for longevity.”