What are the risks of excess vitamin D in the body?

Table of contents

1. Why is vitamin D3 so important for the body?

2. What is the need for vitamin D?

3. Excess vitamin D - can you overdose on vitamin D?

4. Excess vitamin D - symptoms to watch out for

5. Excess vitamin D - symptoms in children

6. Excess vitamin D in pregnancy

7. How to treat vitamin D poisoning?

The properties and benefits of taking the so-called "sunshine vitamin" are known to more and more people. And good luck, because it is one of the most important vitamins for our body. Unfortunately, its deficiency is still a common problem in Poland, where sunshine tends to be scarce. However, there are also increasing questions about the other side of the coin - is excess vitamin D harmful? Interestingly, an excess of this vitamin can be just as dangerous as a deficiency. How does an overdose occur? What are the symptoms? How to get rid of excess vitamin D? Rest assured, we will answer all your questions.

Why is vitamin D3 so important for the body?

Vitamin D has many tasks in our body. First and foremost, however, it supports calcium-phosphate metabolism, so that bones can be properly formed and mineralized. It is what makes the body absorb calcium from food and use it to build strong bones and teeth. A deficiency can therefore lead to a weakened skeletal system, and rickets in children. However, this vitamin is also responsible for the immune system - it reduces the risk of infections and soothes inflammatory processes in the body. It also affects the health of the muscles and nervous system, and may even play a role in preventing depression and autoimmune diseases ^[1].

The body is able to synthesize vitamin D on its own, but only if it has access to sufficient sunlight. In our latitude, this is possible in summer, but in autumn and winter, and sometimes in spring, supplementation is necessary. Knowing the need for vitamin D is therefore essential to avoid overdosing.

What is the need for vitamin D?

Much depends on your age, health, lifestyle, and the moment in life you are currently in. Adults should consume between 800 and 2,000 units per day. However, older people, pregnant women or those struggling with excess weight may need higher doses. For people over the age of 75, the dose of vitamin D is 4,000 IU (100 µg) per day according to the 2021 GIS recommendations, which state the maximum daily dose of vitamin D in dietary supplements. These recommendations are based on current scientific knowledge and are intended to ensure the safety and effectiveness of vitamin D supplementation.

However, it is worthwhile to determine the consumption of vitamin D supplements individually with your doctor based on blood tests. Its optimal level in the body is 30-50 ng/ml. Levels above 100ng/ml can signal an excess of vitamin D.

Excess vitamin D - can you overdose on vitamin D?

Vitamin D overdose, or so-called hypervitaminosis D, is as possible. However, it occurs rarely, which is worth keeping in mind. First of all, remember that the natural synthesis of this vitamin in the skin - even with prolonged sun exposure - does not lead to an overdose. The body regulates its production on its own. What causes an excess of vitamin D? The problem can arise during supplementation and exceeding the safe doses recommended by the manufacturer or doctor. How can this happen? For example, when you supplement various preparations that contain vitamin D. Supplementation by stockpiling can also contribute - when you think that taking several doses of a supplement one day won't hurt you at all. Remember that the recommendations on the package are there for a reason. It is not worth deciding to change them on your own.

Excess vitamin D - symptoms to watch out for

The effects of excess vitamin D can be quite inconspicuous - initially there is weakness, headache or fatigue. They can easily be mistaken for an impending cold. However, over time, excess vitamin D can cause serious problems.

Hypercalcemia is one of the consequences of excess vitamin D. Because it increases the absorption of calcium in the intestines, the body gets too much of it, leading to a condition in which blood calcium levels are too high. This can be associated with muscle and joint pain, for example. This is because calcium is deposited in soft tissues.

What is excess vitamin D associated with? Neurological symptoms, such as irritability, confusion or even memory problems, can occur due to elevated calcium levels in the blood. It directly affects nerve cells, interfering with their functioning. Disruption of nerve impulse conduction, increased excitability of nerve cells - this is an advanced state of hypercalcemia, but as possible.
What else is affected by excess vitamin D? Hair loss is another symptom that is associated with mineral imbalance in the body.
Stomach problems, including abdominal pain, diarrhea and vomiting.
Damage to the kidneys and, in extreme cases, even kidney failure - this is one of the effects that arise with long-term excess vitamin D.

It is worth remembering that these are not problems that arise overnight. However, excess vitamin D can lead to serious consequences. Not only in adults, but also in children, who are even more vulnerable to mineral imbalances.

Excess vitamin D - symptoms in children

Vitamin D overdose can occur even more so in children, who need much smaller doses of the vitamin than adults. Incorrect supplementation leads to:

Lack of appetite, nausea and vomiting, and abdominal pains

Neurological problems such as irritability, weakness, lethargy and impaired concentration.
Development and growth disorders. This is one of the biggest risks associated with vitamin D overdose in children. It can lead to bone deformities, stunted growth and problems with tooth eruption.

How else does an excess of vitamin D manifest itself? A rash is another symptom that should be alarming. Other changes, such as excessive sweating or dehydration associated with frequent urination, should prompt parents to see a doctor right away ^[2].

Excess vitamin D in pregnancy

During pregnancy, the need for vitamins and minerals increases significantly, and vitamin D supplementation is recommended to support both the health of mom and the developing baby. Keep in mind, however, that excess vitamin D during pregnancy can be just as harmful as vitamin D deficiency. Too high doses lead to hypercalcemia, which can result in complications such as high blood pressure and kidney problems. In the fetus, meanwhile, excess vitamin D can interfere with bone development and lead to skeletal deformities. Therefore, be sure to consult your doctor before starting supplementation. It's also a good idea to monitor vitamin D levels in the blood.

How to treat vitamin D poisoning?

If tests indicate too high levels of vitamin D and an overdose of vitamin D, it is necessary to consult a doctor. Treatment of hypervitaminosis D mainly consists of discontinuing supplementation - immediately, so that the body begins to clear it. The doctor may also recommend IV fluids, corticosteroids or bisphosphonates to reduce hypercalcemia, that is, lower calcium levels in the blood. Regular blood tests will indicate whether vitamin D and calcium levels in the body are decreasing. Keep in mind that with mild symptoms, such as headaches or rashes, they may resolve on their own after supplements are discontinued. In more severe cases, treatment may require hospitalization.

If you notice alarming symptoms in yourself, such as a rash, headaches, or hair loss - don't delay consultation. A blood test will quickly show whether this is the result of a vitamin D overdose. Remember that our body needs balance first and foremost, including vitamin balance. Therefore, always exercise caution when supplementing.

Source

^[1] https://www.cambridge.org/core/services/aop-cambridge-core/content/view/F4E7DFBE5A7B99C9E6430AF472286860/S0007125000273418a.pdf/vitamin-d-deficiency-and-depression-in-adults-systematic-review-and-meta-analysis.pdf

^[2]https://www.healthline.com/nutrition/vitamin-d-side-effects#signs-and-symptoms