Vitamin D Deficiency Symptoms

Causes of vitamin D deficiency

As with all of the essential vitamins and minerals, there are benefits to be obtained from ensuring that your body is getting a regular supply of vitamin D. Conversely, if you are unable to get enough of this nutrient then you face the prospect of developing a deficiency, the symptoms of which are generally more severe and wide-ranging for children than for adults.

This page will help you to recognise exactly what the symptoms of vitamin D deficiency are, together with the causes. We will also discuss the best ways to keep your levels of this vitamin topped up and end with information on vitamin D deficiency treatment.

If you are interested in low vitamin D symptoms then you may also find the information included on our page on vitamin D foods and benefits useful as well.


There are two different sets of symptoms of this deficiency; one that relates mainly to children and the second to adults. To make the situation more complex, not all symptoms are likely to be present in each individual, it is often the case that a deficiency is only diagnosed in the more severe cases.

Nonetheless, we have listed these symptoms below so you know what to look out for:

RDI Vitamin D

  • 15µg (600 IU) Adults up to 70 years
  • 20µg (800 IU) Adults over 70 years
  • 15µg (600 IU) Children 4-18 years
  • 15µg (600 IU) Toddler 1-3 years
  • 10µg (400 IU) Infants 0-12 months

Symptoms of lack of vitamin D in adults:

  • Aches and pains both vague and severe
  • Muscle weakness
  • Pain in bones, most commonly in the hips, pelvic region, feet and ribs
  • General tiredness and sense of not being well

In severe deficiency known as osteomalacia, severe pains and muscle weakness that can affect how you walk

Lack of vitamin D symptoms in children and infants:

  • Breathing problems related to associated low calcium levels
  • Cramping and muscular spasm
  • Seizures
  • Increased irritability
  • Stunted growth, height is more commonly an issue
  • Delayed teething in young children
  • Children may be late or unable to start walking properly
  • Severe deficiency can lead to soft leg bones or skull with associated bone pain. The legs may appear bowed. This condition is known as ‘Rickets’

If you recognise these vitamin D deficiency signs, the condition can be diagnosed by a doctor or medical professional by means of a blood test. If you are concerned for yourself or your child it is vital to arrange this as soon as possible.

Causes of Vitamin D Deficiency

There are three main causes of deficiency in this nutrient which we have outlined below:

Increased need for vitamin D – Some people will require more vitamin D than others because there are certain factors inhibiting the way that their body deals with, and/or synthesizes this vitamin. This can include pregnant or breastfeeding women, or the breastfed babies of women who are themselves deficient in vitamin D. The next section goes into more depth as to who is in the ‘at risk’ category.

Not enough vitamin D in your diet – One of the causes of vitamin D deficiency symptoms is that there is not enough of this nutrient in the diet. This can include vegans and non-fish eaters. In order to find out which foods contain this vitamin, please check out our vitamin D foods list page.

Your body is not able to create enough vitamin D – Some people are not able to create enough of this vitamin due to age, medication, illness or other inhibiting factors. In the below section not only do we go into further detail on the people who have an increased need for vitamin D, but we also explain who may not be able to create enough.

Who's at Risk?

Who can display the symptoms of vitamin D deficiency?

Below we have listed groups most at risk of developing a deficiency of vitamin D. If you fit into one of these categories and are experiencing one, or several, of the vitamin D deficiency symptoms that we have listed above then it is very important that you seek medical advice, so that you can get a diagnosis and then if necessary begin to deal with the problem before it becomes more serious.

At risk groups

  • People who are housebound or stay indoors during daylight hours.
  • People who wear robes, veils or other coverings for religious reasons, or whose clothing prevents skin exposure
  • Anyone who lives at very northerly latitudes
  • People with dark skin may need more than 10 times more sun exposure to produce the same amount of vitamin D as those with pale skin, because natural skin pigmentation acts as a natural sunscreen.
  • People who habitually use extremely high factor suncream. While protection from harmful ultra-violet rays is essential, overuse of sunscreens can prevent your body getting sufficient vitamin D.
  • Older people are more at risk for two reasons. Firstly, their skin doesn’t make as much vitamin D in response to sun exposure, and secondly, their kidneys become less efficient at converting this vitamin into the form used by the body.
  • People who have a higher body mass, whether due to fat or muscle – a BMI of more than 30 means an increased risk of deficiency.
  • Certain medical conditions, including Crohn’s, Coeliac disease, and cystic fibrosis, can affect your intestine’s ability to absorb vitamin D from food.
  • Women who are breast feeding have an increased need for vitamin D..
  • Babies who are breast fed by women who are lacking in their vitamin D levels.
  • Vitamin D deficiency symptoms can also occur in people who routinely take certain medications, including some anti-HIV drugs, phenytoin and primidone.
While the above list show people who are most likely to develop vitamin D deficiency symptoms, it is not exclusive. Therefore if you are experiencing the symptoms listed above it is a good idea to speak to a qualified healthcare practitioner and get the necessary treatment if required. For more information please also see further down the page for how to top up your vitamin D levels.

How are low vitamin D levels diagnosed?

If you fear that you are suffering from mild or severe vitamin D deficiency symptoms then it is critical that you speak to your doctor, or other qualified health professional immediately. Information online can help point you in the right direction to recognising what the problem is, however self diagnosis and treatment can be very dangerous. If you seek medical help then they will be able to diagnose low vitamin D levels by taking a blood test. Leaving any symptoms undiagnosed can be a serious risk to your health so we really do urge anyone that believes they are experiencing the symptoms of vitamin D deficiency to seek help.

What is the recommended Vitamin D dosage?

Please see the chart at the top right of this page for the recommended daily intake (RDI) of this nutrient.


Vitamin D deficiency treatment

Now we have covered what causes vitamin D deficiency symptoms, what they are and who is most likely to be at risk from developing them. Next we can discuss the common measures of vitamin D deficiency treatment. When you have been diagnosed with this deficiency, your doctor will go through the best course of treatment for you as an individual. This may include:

  • Eating more vitamin D foods
  • Vitamin D injections
  • Taking medicinal vitamin D as a liquid, powder, or a tablet; these can vary in dosage
  • Take vitamin D supplements

Following treatment, your body will have been able to catch up and re-stock it’s levels of vitamin D.  However, in order to prevent the same thing from happening again you will need to maintain a regular intake of the vitamin. This vitamin D dosage will likely be lower than that of the treatment, but necessary for your long term health.

How to top up your vitamin D levels

In this section we are going to explain the best ways to ensure that you are getting your regular dose of vitamin D.

Sunlight – When your skin is exposed to sunlight, vitamin D is synthesized within your body without the need to consume anything. This is a good reason to get out of the house every day in order to experience real sunlight, as artificial light does not trigger the body to produce vit D. For a fair-skinned person, it is estimated that 20-30 minutes of sunlight on the face and forearms 3 times a week during the summer months in the UK is sufficient to maintain normal vitamin D levels. The sunlight has to fall directly on your bare skin – through a window isn’t enough.

Vitamin D foods – As you will see on our vitamin D foods list page, there is a range of foods that are all brilliant natural sources of this nutrient. If you can incorporate these foods into your diet then you will greatly reduce your likelihood of developing vitamin D deficiency symptoms. The best dietary sources of vitamin D are oily fish and cod liver oil. In the UK, there is little or no vit. D in milk and dairy products, and only infant formula milk and margarine have statutory vitamin D supplementation.

Supplements – You can get almost any nutrient from supplements, either singly or as part of a multivitamin. However, because vitamin D supplements can have an effect on some medications, please consult a medical professional before starting to take them.

And finally…

We encourage you to look at the above sources as a collective and not as an ‘either or’ option when it comes to getting your vitamin D. Don’t just assume a walk out in daylight each day (particularly in winter) will get a sufficient amount of this vitamin, or that supplements alone will do the trick. A combination of these sources is the best way to prevent the onset of low vit D deficiency symptoms.

For further information on why this nutrient is so important (besides preventing the chances of vitamin D deficiency symptoms of course), please have a look at our page on the benefits of vitamin D as there are many wonderful things that it can do for your health. Making a conscious effort to keep up your levels of this and other essential vitamins and minerals that we have mentioned on this site, you are going a long way to ensuring the successful long term health of your body.