The symptoms of too much vitamin D

Vitamin D helps keep your bones healthy and supports your immune system. It is not for nothing that vitamin D is one of the most popular vitamin supplements available. But is it also possible to get too much vitamin D? And what are the symptoms of too much vitamin D? In this article we will explain it to you, so keep reading. 
 

The Netherlands Nutrition Centre recommends a daily intake of 10 micrograms of vitamin D per day. This is actually the minimum amount your body really needs through your diet. Because your body does produce vitamin D largely in your skin, under the influence of sunlight. Yet that is far from enough for everyone.

Not everyone gets enough sun and moreover, the strength of the sun in the Netherlands is not always the same. Older people and children also produce too little vitamin D in the skin. And besides that, people of color or people with darker skin produce too little vitamin D in the skin. A supplement, to complement your diet, helps you to meet your vitamin D needs.

Read more about the risk groups that produce less vitamin D? Read more here and learn which dosage is appropriate in the article 'How much vitamin D per day?'.

It is no problem to use more than 10 micrograms of vitamin D in a supplement. In Europe, the maximum dose for vitamin D3 supplements is set at 100 micrograms per day. In the Netherlands, the permitted amount is slightly lower: namely 75 micrograms per daily dose. A supplement of, for example, 25 micrograms is therefore a safe value between the amount you need at least and the amount you are allowed to take at most.

Never take more than the recommended amount in the instructions for use of your supplement.

A blood test can give you a definitive answer about your vitamin D level. But what do these values actually say and what value are you aiming for?

According to the general European guidelines, a blood level of 50-75 nmol/L is considered sufficient for most people. Anything below the value of 50 is considered a deficiency. 

According to the guidelines of the Dutch College of General Practitioners, the target value for vitamin D is 30 nmol/L for adults under 70 years. For older people, the target value is 50 nmol/L. There is some discussion about whether those guidelines should not be adjusted upwards, towards the European values, given the importance of Vitamin D for health¹.
Orthomolecular therapists, who use nutrients to strive for optimal health, often even aim for even higher values.

Because you produce vitamin D in your skin under the influence of the sun, vitamin D is also called the sunshine vitamin. Are you in the sun for a long time and has your body produced enough vitamin D? Then your body will not continue producing it endlessly. There is a natural mechanism to regulate the production of vitamin D, where the skin stops producing vitamin D as soon as the need is met. This helps prevent an excess of vitamin D.

So too much vitamin D in your body as a result of exposure to the sun is not possible. It is also rare to get too much vitamin D through food alone. Natural food sources of vitamin D, such as fatty fish, meat and eggs, do not contain large amounts of vitamin D. So the risk of getting too much vitamin D through food is therefore generally very low.

Too much vitamin D is quite rare. The biggest risk of too much vitamin D comes mainly from long-term intake of high doses of vitamin D supplements. Vitamin D is a fat-soluble vitamin that you can store in your body. It is therefore important not to take more than is recommended in the instructions for use of your supplement.

So too much vitamin D can practically only occur by taking too many, high-dose vitamin D supplements for a long time. Complaints that can arise from this are: 

1. Fatigue and weakness;
2. Nausea, vomiting and reduced appetite;
3. Increased thirst and frequent urination;
4. Increased calcium levels in the blood;
5. Bone pain and bone changes.

It is important to note that these symptoms vary in severity. Also, the presence of one or more of these symptoms does not automatically mean that there is a vitamin D excess. If you suspect that you are dealing with a vitamin D overdose, consult your doctor for a proper diagnosis and treatment.

It is always important to follow the recommended dosages of vitamin D supplements and to seek advice from a healthcare provider when using high doses.  

Sources:

[1] Heaney RP, Holick MF. Why the IOM recommendations for vitamin D are deficient. J Miner Res 2011;26:455-7.