Approximately one-third of the American population is at risk for vitamin deficiencies or anemia , also known as iron deficiency. People are starting to become aware of more common nutrient deficiencies , such as vitamin D and magnesium, which is good news. Yet many don’t know whether they themselves have a deficiency, or how they might go about finding out if they have any.
Nutrient and vitamin deficiency testing via blood test isn’t a standard part of wellness check-ups. It’s the kind of thing that tends to get investigated only when a person is showing obvious signs of deficiency. The problem is, the symptoms of vitamin and mineral deficiency can range from very noticeable to super subtle. Often, they’re on the less-obvious side.
“Many of these signs and symptoms are easy to blame on something else, like being stressed or dealing with a tight work deadline,” explains Katie McHugh , RD, a health coach at Parsley Health.
Some of the possible symptoms of vitamin and mineral deficiency, she says, include:
Of course, some of these symptoms are more noticeable and troubling than others. If you’re experiencing any of them, it’s important to talk to your health care provider so they can identify what’s going on and treat you accordingly, McHugh says. At Parsley Health, that process starts with in-depth lab work that includes vitamin deficiency testing.
But unfortunately, vitamin deficiency testing is also not always readily offered in conventional medicine settings, and this is one of the reasons deficiencies can go on for a long time before being discovered. “If you have a great primary care physician (PCP) and ask them to test you for specific vitamin deficiency, they’d probably hear you out on it,” McHugh says. But that assumes you have a doctor who is open to your suggestions and that you yourself are aware of the signs and symptoms of deficiencies. For most people, that’s just not the case.
Diet is one of the biggest contributors. “We have dietary reference intakes, or DRIs, and that’s how much you should be eating of each nutrient,” McHugh explains. “With our Standard American Diet, research shows we do come in quite a bit lower on certain nutrients.”
For both people who do eat enough of each nutrient and those who don’t, absorption issues can also be at play. “Most of our nutrients are absorbed in our small intestine. If there’s something going on with the small intestine, that can certainly impair nutrient absorption.” So people with conditions that affect the small intestine, like IBD, Crohn’s disease, and celiac disease are at a higher risk for deficiencies, McHugh says.
Certain medications can also have this effect, such as methotrexate.
Lastly, aging can affect your body’s ability to absorb nutrients. For instance, as we get older, we have less stomach acid and intrinsic factor, a protein secreted by your stomach, McHugh says. We need intrinsic factor to absorb vitamin B12, so B12 levels often decrease with age.
Micronutrients, like vitamins and minerals, are essential for every biochemical reaction in your body, McHugh explains. “That’s what we’re talking about with absorption. There are reactions going on in your intestines as well as throughout your body, and it’s important to have everything up to full speed.”
Think of your body like a house. “Not having enough nutrients is like building a house with poor construction materials. Eventually, things are going to fall apart,” McHugh says. This is why testing for vitamin deficiencies is so important. Without testing, you’re likely to find a band aid solution that only temporarily solves your problems. For example, if you have eczema , you might be given a steroid cream to treat it. “But it might not actually ever go away completely, because you’re not looking upstream to solve the deficiency that’s causing it,” McHugh explains.
There’s another big reason vitamin deficiency testing is key: Long-term deficiencies can cause long-term problems.
Take vitamin D , for example. “Most people think they need calcium for healthy bones,” McHugh says. But vitamin D (along with vitamin K) is crucial for bone health, as well. Let’s say you don’t get enough vitamin D in your 20s and 30s. By the time you’re 40 or 50, especially if you’re a woman, you would be at a much higher risk for osteoporosis due to that deficiency, aging, and other factors. “When you get to age 60 and you’ll have low vitamin D and cracked bones, you’re going to be wishing you found that vitamin D deficiency earlier on,” McHugh adds.
In a way, testing for these deficiencies can be pretty empowering. “I think it goes to being able to prevent one of these more serious conditions from coming on,” McHugh says. “The idea that you can change health outcomes by modifying your diet or taking supplements is pretty cool.” And it’s not always some intense protocol you need to follow to have this effect. “It could be as simple as changing how many leafy greens you eat every day for more magnesium, or taking a magnesium supplement if needed.”
There are a few different ways to get vitamin deficiency testing, and they each have their pros and cons.
Many PCPs will check a specific nutrient level via a blood test if you ask for it and explain why you want to have it tested. Certain nutrient deficiency tests, like vitamin D, vitamin B12, magnesium, and calcium are commonly used in mainstream medicine settings. But it’s not common to do a whole panel of these tests in this setting, so you’ll have to know what you’re looking for in terms of deficiencies and really advocate for yourself, McHugh says. If you have no idea what may be causing your symptoms or what vitamin you may be deficient in, this method can be tough to get the clearest picture from.
These often use a finger prick blood sample, rather than the full vial that would be drawn at a doctor’s office or lab. One big upside of these is that they can be done from the convenience of your home.
A downside, though, is that we don’t know how effective they are. “I don’t think there’s enough research on at-home test kits,” McHugh says. Plus, they vary in quality, and there is more room for error when you’re the one drawing your own blood sample. You might not provide enough blood for accurate results, or accidentally contaminate the sample, for example.
Another con is that you may not have a doctor to interpret your results or create a care plan if you do have a deficiency. “Everyone’s so individualized that there isn’t a blanket dose for vitamin D or magnesium,” McHugh says. “So having the supervision of a doctor is super important.” Also, doctors are able to prescribe therapeutic doses of supplements, which may be much higher than that’s available for the public to purchase.
If you decide to go the at-home route, McHugh recommends ensuring the testing company works with a certified lab. Also, choose a test that works off of a blood sample rather than a hair sample. “Hair samples are great for DNA, but they don’t show recent changes in the body. So these tests might not be indicative of your most recent nutrient status.”
Lastly, you could work with a holistic medical provider, like Parsley Health. “At Parsley, the doctors order the labs, and they do a very in-depth intake for all of our members. Our baseline Parsley panel is much more comprehensive than what would be done at a typical PCP,” McHugh says. “If nutrient deficiencies aren’t on your radar, they’ll be on your doctor’s.”
And if testing reveals you do have a deficiency, your doctor will follow up with periodic testing, to ensure whatever treatment you’re using is working. Plus, you’ll have an opportunity to work with a health coach, who can look at diet and lifestyle factors that might be contributing to a nutrient deficiency.
One of the reasons this approach is so effective is that vitamin deficiencies are often intertwined with other health issues, making it difficult to unravel the root cause. For instance, if a person has dry, cracking skin, they might initially blame it on cold weather. Then, they get it checked out and discover they have a vitamin deficiency. Upon digging a little deeper, their doctor might discover they have leaky gut , which is limiting nutrient absorption, causing the deficiency and thus, the dry skin.
This is really what differentiates getting tested with a holistic medicine doctor from working with your PCP or doing at- home-test. It’s all about getting to the root cause.
Julia Malacoff is an Amsterdam-based freelance writer, editor, and certified personal trainer. She covers a wide range of wellness topics including nutrition, fitness, specific health conditions, and the latest scientific research in these field. Julia graduated from Wellesley College and she works with brands like Shape, Cosmopolitan, Fast Company, Precision Nutrition, Equinox, and Aveeno. Outside of work, you can find her walking her dog, trying out a new recipe, or learning Dutch.