"I'm tired all day, but the doctor says everything is fine." It is one of the most common sentences among over-60s. And it is confusing, because you feel that something is off, while the standard result reassures. Sometimes that tiredness really does belong to a busy week or a bad night. But sometimes there is a cause behind it that is easy to find, and that is precisely the one you do not want to miss.
My view: fatigue in older adults is brushed aside far too easily as "it just comes with age". That is sometimes true, but it is no reason not to look. A shortage of vitamin B12, iron or vitamin D is more common in later life and can quietly drain your energy. And those are exactly the things you can get back. In this guide you will read which blood values can explain fatigue, how to look at them together, and when a test makes sense.
Why do you feel tired more often with the years?
Fatigue rarely has a single cause. Sleep, movement, medication, mood and loneliness all play a part. In addition, something changes in the body: some nutrients are absorbed less well in later life, so deficiencies build up unnoticed. The stomach makes less acid, appetite can decline, and the diet sometimes becomes more one-sided.
That makes it hard to judge by feeling what is going on. A blood test can reveal a number of possible causes you cannot see from the outside. Importantly, a blood test does not explain all fatigue, but it does pick up the causes linked to diet, medication or the thyroid. That is often exactly the part that is treatable.
Which deficiencies cause fatigue in older adults?
Three deficiencies stand out in over-60s. They have in common that they are common, that they develop quietly, and that they show up with a simple blood test.
Vitamin B12
A shortage of vitamin B12 is more common in later life, because the stomach makes less acid over the years and B12 is therefore absorbed less well. Acid-reducing drugs and the diabetes medicine metformin can add to this. A B12 deficiency can cause fatigue, but also tingling in the hands or feet, an unsteady gait and forgetfulness. The Netherlands Nutrition Centre (Voedingscentrum) names older adults, vegetarians and vegans as groups at increased risk of a B12 deficiency.
Iron and anaemia
Too little iron can lead to anaemia, in which your blood carries too little oxygen. That causes tiredness and breathlessness on exertion. The iron store itself is read from your ferritin, which often falls first. The Dutch College of General Practitioners (NHG) stresses that with anaemia it is the underlying cause that counts, such as unnoticed blood loss. For the details, read our guide on anaemia in older adults.
Vitamin D
In later life the skin makes less vitamin D from sunlight, and many older people spend less time outdoors. A shortage can go together with fatigue and muscle weakness. The Nutrition Centre advises everyone from age 70 to take 20 micrograms of vitamin D daily, advice that goes back to the Health Council of the Netherlands (Gezondheidsraad). You can have these three values measured in one go with the Vitamin and Iron Panel from Levenswijs.
What does your thyroid have to do with energy?
The thyroid helps regulate your metabolism, the pace at which your body uses energy. If the thyroid works slowly, it can cause fatigue, feeling cold, sluggish bowels and weight gain. A mild, slow thyroid is more common in later life, and the symptoms look deceptively like "just getting older".
The value involved is your TSH, the hormone that drives the thyroid. An abnormal TSH is a reason to look further, in consultation with your GP. Precisely because the symptoms are so general, a measurement is useful to distinguish a thyroid that needs attention from tiredness with another cause.
And blood sugar? The silent energy thief
A high blood sugar can, paradoxically, cause fatigue, together with frequent urination and thirst. Type 2 diabetes often develops gradually and goes unnoticed for a long time. The value that shows the long-term average of your blood sugar is the HbA1c. The National Institute for Public Health (RIVM) tracks how often diabetes occurs through population research and its Public Health Foresight Study, and those figures show that the risk rises with age. A raised blood sugar is therefore a cause of tiredness you do not want to skip.
Which blood values should you check for fatigue?
With persistent fatigue it is wise to look at the most common causes in one go, rather than one value at a time. That way you avoid having to return for another blood draw. The table below is your decision aid: it links a possible cause to the symptom and to the sensible check.
| Possible cause | Symptoms that may fit | Sensible check |
|---|---|---|
| Vitamin B12 deficiency | Tiredness, tingling, unsteady gait | Vitamin and Iron Panel |
| Iron deficiency or anaemia | Tiredness, breathlessness, paleness | Vitamin and Iron Panel |
| Vitamin D deficiency | Fatigue, muscle weakness | Vitamin and Iron Panel |
| Slow thyroid | Sluggishness, feeling cold, weight gain | TSH check (in consultation with the GP) |
| High blood sugar | Tiredness, frequent urination, thirst | Diabetes Panel |
The strength lies in the combination: one blood draw, several possible causes in view. A result within the reference ranges does not rule out everything, but it does make the known, treatable causes visible.
"Normal" is not always the same as "enough"
A common confusion: a value sits just within the reference range and the result is called "normal", while you do not feel fit at all. That can be the case, and it deserves an explanation. A reference range is the range in which most healthy people fall, not automatically the range in which you feel your best. This plays out especially with vitamin B12. A value at the low end of normal can still cause symptoms in some people.
That is why a doctor sometimes looks beyond the ordinary B12 value. In doubtful cases an additional measurement can help, for example the active form of B12 or a breakdown product that rises with a functional deficiency. The Dutch College of General Practitioners (NHG) advises always judging a B12 result together with the symptoms, and not relying blindly on a single number. My advice fits with this: take both your symptoms and your numbers seriously, and discuss them together.
Silent inflammation: the lesser-known energy drainer
Besides deficiencies, long-standing low-grade inflammation can also go together with fatigue. The body is then constantly in a mild state of alert, which costs energy. The value that can say something about this is the CRP, a protein that rises with inflammation. A raised CRP is not specific: it says that something is going on, not what. But together with the other values and your symptoms it can help your GP complete the picture.
It is important to realise that a one-off raised CRP can simply be due to a recent cold. A single measurement therefore says little. The pattern over time, together with the other values, is what counts. This is exactly why a doctor looks at the whole rather than at single numbers.
How do you read your result in context?
A common mistake is to judge each value on its own. Fatigue is better understood by placing values next to each other. A few examples of how a doctor can read patterns, purely as illustration and never as a replacement for a real consultation:
- A low ferritin with a still-normal haemoglobin can point to a shrinking iron store, before there is true anaemia. An early signal, then.
- A low B12 together with tingling weighs more heavily than a low B12 without symptoms. The combination gives direction.
- A slightly abnormal TSH with clear symptoms of sluggishness and feeling cold is a reason for a doctor to look further, while the same TSH without symptoms is sometimes simply monitored.
- A raised blood sugar together with a lot of thirst and urination calls for faster action than a borderline value without symptoms.
The pattern tells the story, not the single number. That is why it is so valuable to have several values measured at once and to discuss the result together with your GP.
What if your values are "normal"?
Suppose your B12, iron, vitamin D and thyroid are all fine, and yet you are tired. That happens, and it does not mean you are imagining things. Fatigue can also relate to sleep, movement, medication, mood or loneliness. A normal blood result is then valuable in itself: it rules out a number of physical causes, so that together with your GP you can look more specifically at the other side of the story.
My advice here: do not see a blood test as the answer, but as one building block. It tells you what the blood does and does not explain. That alone is a kind of reassurance.
Practical lifestyle tips for more energy
Beyond finding deficiencies, there is much to gain through lifestyle. No miracle cures, but things that add up:
- Move daily, even if it is a short walk: movement often makes more energy than it costs
- Eat varied, with enough protein, vegetables and wholegrain products
- Keep a regular sleep rhythm and be careful with long daytime naps
- Drink enough, because older people feel thirst less quickly and dehydration causes tiredness
- Ask your pharmacist whether one of your medicines can cause fatigue as a side effect
When is fatigue a reason to have your blood tested?
If the fatigue lasts longer than a few weeks, or comes with symptoms such as tingling, breathlessness, paleness or frequent urination, a blood test is a logical step. You can have these values checked at Levenswijs without first obtaining a referral.
If you would first like to understand the bigger picture, read how your blood values change after 60. If your kidney function or medication also plays a part, see medication and your kidneys. And if you are thinking about your bones, read our guide on bone loss, calcium and vitamin D.
My closing advice: take persistent tiredness seriously, but do not panic over one low value. A deficiency is often very treatable, and a normal result brings reassurance. Always discuss an abnormal result with your GP, because a blood test does not make a diagnosis on its own and is a tool, not a final verdict.
Frequently asked questions
Isn't being tired in later life simply normal?
A little less energy can come with ageing, but persistent, troublesome fatigue is not a given. It can point to a deficiency or a slow thyroid, which are often very treatable. Discuss it with your GP.
Do I need to fast for this blood test?
For vitamins, iron and TSH you usually do not need to fast. If your blood sugar is also measured via a fasting glucose, fasting may be needed. Follow the instructions with your test.
How quickly will I notice improvement if I correct a deficiency?
That differs per person and per deficiency. For some deficiencies it can take weeks to months before you notice a difference. Discuss a suitable approach and follow-up with your GP.
Can I have all values measured in one test?
The most common causes of fatigue can largely be checked in one go with the Vitamin and Iron Panel, optionally supplemented with a thyroid or blood sugar check. Which combination suits you is something to discuss with your GP.
Frequently asked questions
Is being tired after 60 just age?
Sometimes, but far from always. Shortages of B12, iron or vitamin D and an underactive thyroid are more common later in life and cost energy. A blood test can help tell apart what is going on.
Which test makes sense for fatigue?
The Vitamin and Iron Panel measures B12, iron and vitamin D in one go. With persistent complaints, a thyroid check (TSH) or a Diabetes Panel can also be useful.
Why do older people more often have a B12 deficiency?
With age the stomach makes less acid, so B12 is released less well from food. Acid-reducing drugs and the diabetes medicine metformin can add to this.
Do I need a referral?
No. At Levenswijs you can have your vitamins and iron measured without a referral. The result is reviewed by a doctor registered in the Dutch BIG register. For treatment, your GP remains your point of contact.
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