3 Nutrient Deficiencies Worth Checking as You Age

When was the last time you looked closely at your bloodwork?

Most people get some version of annual screening labs, but there are a handful of important nutrients that aren't always included in standard bloodwork. And when we're thinking about healthy aging, brain health, energy, and longevity, these can be worth paying attention to.

At Flourish, we see nutrient deficiencies all the time—sometimes even in people who eat a healthy diet and are doing many of the “right” things.

The reason is that it's not always about what you're eating. As we age, our ability to absorb and utilize certain nutrients can change. Stress can affect digestion and nutrient status. Blood loss can deplete iron stores. And sometimes, what looks like anxiety, fatigue, brain fog, or simply not feeling like yourself may be worth investigating from a nutritional perspective.

The good news is that these are often some of the low-hanging fruit. Before jumping to complicated solutions, it can be incredibly valuable to make sure the basics are covered.

Here are three areas we think are worth knowing about.

1. Vitamin B12

B12 is one of those nutrients that we think deserves much more attention, particularly as we get older.

B12 is important for energy production, brain function, memory, mood, the nervous system, and cellular repair. And yet, B12 isn't always included in routine screening bloodwork.

One reason B12 becomes more important with age is that our stomach produces less intrinsic factor, which is needed to absorb B12 from food. So you can be eating meat, eggs, or other B12-containing foods and still have difficulty getting enough.

Stress can also affect digestion and absorption.

And this isn't only an issue for older adults. We see low B12 in younger people, too, particularly when stress is high, sleep is poor, and diets aren't particularly nutrient-dense.

Why does B12 matter for brain health?

Low B12 can be associated with fatigue, brain fog, changes in mood, anxiety, depression, and nervous system symptoms. You don't necessarily have to have obvious neurological symptoms for B12 status to be worth looking at.

Another important piece is that “normal” doesn't always tell the whole story.

B12 reference ranges can be quite broad. Dr. Hillary often looks for more robust B12 levels rather than simply asking whether the result falls inside the laboratory reference range.

There are also more advanced ways to investigate B12 metabolism, including markers such as methylmalonic acid and homocysteine. Genetic testing may provide another layer of information about how an individual processes and utilizes B vitamins.

For now, the simplest place to start is to know your B12 level. If it hasn't been checked recently, ask your healthcare provider whether it makes sense to add it to your next round of bloodwork.

2. Ferritin: Your Iron Storage

The next one is ferritin, which tells us about your body's iron stores.

This is particularly important for women who regularly lose blood through menstruation, as well as anyone who has experienced significant blood loss, including from an accident or surgery.

Here's the interesting part: you can have low iron stores before your standard blood count tells you that you're anemic.

Dr. Hillary recently saw a patient who was struggling with anxiety, depression, and brain fog after significant blood loss. Her ferritin was just 3, yet her hemoglobin hadn't technically dropped far enough to be flagged as anemia. Looking more closely at her previous labs revealed that her iron stores had fallen dramatically.

That's why looking only at the CBC isn't necessarily enough. Ferritin gives us another piece of the picture. For women who have heavy periods, endometriosis, fibroids, or are moving through perimenopause and experiencing more frequent or heavier bleeding, maintaining adequate iron stores can be particularly challenging.

And, importantly, more iron isn't necessarily better. Ferritin can also be elevated in response to inflammation, which is why these numbers need to be interpreted in context by someone who understands the full picture.

So if you're tired, experiencing brain fog, feeling depleted, or have a history of significant blood loss, it's worth asking whether you know what your ferritin is.

3. Zinc

The third nutrient we want to put on your radar is zinc.

Zinc is a trace mineral that plays an important role in immune function, tissue repair, skin health, hair and nails, and many other processes throughout the body. It's also relevant to hormone health and reproductive function.

And here's the problem: zinc isn't usually part of standard screening bloodwork.

It can also be tricky to test. At Flourish, Dr. Hillary often looks specifically at RBC zinc (red blood cell zinc) because it can provide a better picture of zinc status than a standard serum zinc test.

Zinc status can be affected by stress, digestion, diet, and how well we're absorbing nutrients.

And stress is a recurring theme here. When we're under significant stress, we're not always eating well, our digestion may not be working optimally, and the body can use up certain nutrients more quickly.

Zinc deficiency can show up in a variety of ways, including fatigue, brain fog, getting sick frequently, changes in hair, skin, and nails, and even changes in your sense of smell or taste.

For women, zinc can also be relevant to menstrual cycles and ovulation; for men, it plays a role in immune health, healing, and hormone function.

Again, the first step isn't necessarily to start taking a supplement. It's to find out where you are.

Don't Just Look for What's Wrong

This is really the bigger philosophy behind all of this.

Our healthcare system is often designed around finding disease. But there is so much value in asking a different question:

What does my body need right now?

If you're experiencing anxiety, depression, fatigue, brain fog, or insomnia, it doesn't mean that a nutrient deficiency is necessarily the cause. But it can be worth ruling out some of these basic, relatively easy-to-address issues before moving on to more complicated questions.

Think of it like a bucket. If there are holes in the bucket, you can keep pouring more water into it—but you're still going to lose water through the holes. Sometimes our job is simply to find the holes and patch them.

That might mean identifying a B12 deficiency, replenishing depleted iron stores, addressing low zinc, making sure you're getting enough protein or essential fatty acids, or simply taking a closer look at the foundational pieces that support your health.

These may seem like small things, but they give your body the basic building blocks it needs to function well. And sometimes, addressing those basics can make a surprisingly meaningful difference.

Longevity Starts With the Basics

When we talk about longevity, it's easy to get distracted by the newest test, supplement, medication, or wellness trend.

But healthy aging really does come back to the basics.

Eat well. Move your body. Get enough protein. Hydrate. Get your essential fats. Manage stress. Get enough sleep. And know what's happening inside your body.

You don't have to do everything at once.

Start by looking at your most recent bloodwork. Ask whether B12 and ferritin have been checked. Consider whether zinc testing makes sense for you. And if you're interested in understanding your individual biology more deeply, talk with your healthcare provider about whether genetic testing or more advanced nutrient testing could be useful.

You can't make informed decisions about your health without information.

Testing isn't about finding something wrong with you. It's about getting curious, identifying the low-hanging fruit, and giving yourself the opportunity to support your body before a small problem becomes a bigger one.

That's a pretty good place to start when it comes to healthy aging.

Get Ahead of Disease: Upcoming Events at Flourish

If this conversation has you thinking, “I should probably know more about what's going on inside my body,” we have two opportunities coming up to learn more.

Empowered Wellness Collective: Getting Ahead of Disease — Essential Health Screening

Monday, September 14

Join us for a deeper conversation about the health screenings and testing that can help you become more proactive about your health, including the basic bloodwork and other tools that can give you a clearer picture of what's happening inside your body.

Galleri Cancer Screening

Friday, October 9

Join us at Flourish for a dedicated Galleri testing day and learn more about this blood-based approach to multi-cancer early detection and whether it may be an appropriate screening tool for you.

At Flourish Marin Integrative Medicine, we believe healthcare should be about more than simply waiting for something to go wrong.

The more we understand about your unique body, the more thoughtfully we can support it.

And sometimes, the most powerful place to begin is with the basics.