Vitamins and minerals testing for women: which blood values

Want to know which vitamins and minerals you should test as a woman? The deficiencies that occur most often in women are iron (ferritin), vitamin B12, vitamin D, folate, magnesium and zinc. A blood test of these values gives you an honest starting point to understand fatigue, concentration problems or a low mood, together with your doctor. In this article you will read, per deficiency, which symptoms fit, which blood value gives insight and how reliable that test actually is.

I notice that many women walk around with vague complaints for years before anyone suggests simply having their blood drawn. It does not have to be that way.

Which vitamin and mineral deficiencies are most common in women?

In women, deficiencies of iron, vitamin B12, vitamin D, folate, magnesium and zinc occur most often. This is partly due to menstruation, pregnancy and menopause, and partly due to nutrition and how much sunlight you get. Not every deficiency causes immediate symptoms, but together they explain a large part of the fatigue many women struggle with.

Iron loss through menstruation is perhaps the best-known cause. Every month you lose blood, and with it iron, which can slowly deplete your stores. In women with heavy periods this happens faster than many people think.

Vitamin D is another example tied to our lifestyle. In the Netherlands the sun sits too low for a large part of the year for your skin to make enough vitamin D, certainly between October and April. According to the Health Council of the Netherlands, many women therefore get too little in winter, especially if you spend little time outside or have darker skin.

Vitamin B12 and folate play a role in making red blood cells and in your nervous system. A deficiency often creeps in slowly, sometimes through diet (for example with a plant-based diet) and sometimes because your body absorbs B12 less well.

Magnesium and zinc get less attention, but here too we regularly see lower values, for example with a lot of stress, a one-sided diet or gut complaints.

Which symptoms fit which deficiency?

Many symptoms of a deficiency overlap: fatigue, poor sleep and concentration problems fit several deficiencies at once. That is why you cannot recognise a deficiency from your symptoms alone. The table below links common signals to the blood value that can give insight, as a starting point for a conversation with your doctor, not as a diagnosis.

See this table as a compass, not as a result. The same symptom can belong to several values, and sometimes there is no deficiency at all but something else is going on, such as a thyroid problem or simply too little sleep.

Want to go deeper into a specific deficiency? Then read, for example, our detailed guides on vitamin B12 deficiency: symptoms and testing and on vitamin D deficiency in women.

Deficiencies per life stage: cycle, conception and menopause

Your need for vitamins and minerals changes with your life stage. During your fertile years iron loss through menstruation plays the biggest role, around a wish to conceive folate is added, and in and after menopause attention shifts to bones and vitamin D. So it makes sense that you do not have to check the same values your whole life.

In your menstruating years, iron is the key word. The heavier and longer your period, the greater the chance that your iron stores slowly drop. A low ferritin can already cause symptoms before there is real anaemia, something we discuss in detail in our article on iron deficiency without anaemia.

Do you wish to conceive? Then folate becomes important. The advice of the Netherlands Nutrition Centre is to start with folate before pregnancy, because it plays a role in the early development of the baby. A blood test can help you see where you stand.

Around menopause a lot changes in your body, and that is completely natural. Fluctuating hormones can coincide with symptoms such as fatigue and poor sleep, which can make it hard to know whether a deficiency is involved. That is exactly when a broad blood test can bring peace of mind, because you see what is and is not going on.

After menopause, attention shifts to bone health, where vitamin D and sometimes calcium play a larger role. The good news is that a few targeted values already give you a clear picture.

Which blood values should you test?

For a complete picture, as a woman you usually test ferritin, Hb, vitamin B12, folate, vitamin D (25-OH), magnesium and zinc. This combination covers the most common deficiencies and together gives an honest insight into your vitamin and mineral status. Exactly which values are useful depends on your symptoms and life stage.

A handy base looks like this, for example:

• Ferritin: your iron stores, often the first to drop in women. Read more on our ferritin page.
• Haemoglobin (Hb): shows whether anaemia is already present.
• Vitamin B12: for your nervous system and blood production, see the vitamin B12 marker.
• Folate: important when trying to conceive, see the folate marker.
• Vitamin D (25-OH): the best measure of your vitamin D stores, see the vitamin D marker.
• Magnesium and zinc: supportive, especially useful with targeted symptoms.

Want these values drawn all at once? Our extended health checkup combines vitamins, minerals and a number of other important values, so you get a broad picture in a single appointment.

Not sure which values suit you? Discuss your symptoms with your GP or let your life stage guide you.

How reliable are these tests?

Most vitamin and mineral tests in blood are reliable, but not all are equally precise. Ferritin and vitamin D (25-OH) are considered strong markers, while magnesium and zinc in blood sometimes give an incomplete picture. It is good to know which test measures what, so you place the result in the right context.

For iron, ferritin is usually more informative than the separate iron level in your blood, because ferritin reflects your stores and iron can fluctuate strongly during the day. Ferritin can be temporarily raised with inflammation or infection, so the result is always interpreted together with the rest.

For magnesium there is a known limitation: the magnesium in your blood serum represents only a small part of the total in your body, because most of it sits in your cells and bones. A normal serum value does not fully rule out a deficiency in your cells, and intracellular measurements are difficult in practice.

Also zinc in plasma is a relatively weak marker, because the value can fluctuate due to, for example, a recent meal, inflammation or the time of the draw. That does not mean the test is worthless, but it does mean one result is sometimes not enough to draw firm conclusions.

For vitamin D, the 25-OH form is the standard, because it best reflects your stores. Vitamin B12 and folate are generally usable, although B12 can in some cases need additional investigation if the result does not match your symptoms.

In short: a blood test gives you valuable insight, but no single test tells the whole story. That is why a doctor always looks at the whole picture.

What if you have a deficiency?

If you have a confirmed deficiency, the first step is calm rather than panic. Many deficiencies can be addressed well with nutrition, lifestyle or supplements, in consultation with your doctor. Which approach fits depends on how large the deficiency is and what the cause is, so a result is a beginning, not an endpoint.

With a mild iron deficiency, attention to your nutrition can already help, while a larger deficiency sometimes requires supplementation. We discuss practical steps in our article on preventing iron deficiency with nutrition, supplements and testing. Mainly recognise the fatigue and paleness? Then also read about anaemia symptoms in women.

For other deficiencies, something similar applies. With low folate you can turn to our guide on folate deficiency: symptoms and when to test. Do you mainly suffer from cramps and poor sleep? Then our article on magnesium deficiency in women will help you further. And with reduced immunity or loss of taste, our guide on zinc deficiency in women is a good starting point.

What I often tell women: do not just start high doses of supplements on your own. Too much of certain vitamins or minerals can also be harmful, and some deficiencies have an underlying cause that needs to be found first.

A retest after a few months shows whether your approach works. That way you are not guessing, but really know whether you are back on track.

Frequently asked questions

Can you recognise a vitamin deficiency without a blood test?

Sometimes, but far from always reliably. Symptoms such as fatigue, tingling or pale skin can point to a deficiency, but they fit several causes at once. A blood test gives clarity you cannot get from symptoms alone, and prevents you from taking supplements for nothing.

Which vitamins are especially important for women?

For women, iron (ferritin), vitamin D, vitamin B12 and folate often stand out, partly due to menstruation, conception and menopause. Magnesium and zinc are valuable with targeted symptoms. Which ones are important for you depends on your life stage and what you notice.

How often should you test your vitamins?

If you have no symptoms, yearly or once every few years is often enough. If you have had or treated a deficiency, a retest after a few months is useful to see whether it recovers. With persistent symptoms, it is best to consult your GP.

Do you need to fast for vitamins and minerals?

For most vitamin and mineral tests, fasting is not strictly necessary, although for some values it can help to measure comparably. Always follow the instructions you receive with your test, so the result is as reliable as possible.

Sources

1. Health Council of the Netherlands (Gezondheidsraad). Evaluation of the dietary reference values for vitamin D (2012, with later guidance).
2. Netherlands Nutrition Centre (Voedingscentrum). Vitamins and minerals: folate, iron, vitamin B12 and vitamin D (2023).
3. NHG-Standaard. Anaemia and key points on iron deficiency in general practice (2014).
4. RIVM. Intake of vitamins and minerals in the Dutch diet, Dutch National Food Consumption Survey (2021).

Every blood test result through Lunara includes a professional assessment by a BIG-registered doctor. For treatment decisions, discuss your results with your GP.