Vitamin D poisoning is rare, but it occurs when taking very large doses of vitamin D.
Because excess vitamin D can build up in the body, toxins will spread over time.
Most cases of vitamin D overdose are caused by taking a large supplement.
Sun exposure or food nutrition is almost impossible to cause excess vitamin D.
This article will detail the vitamin D toxicity and how much is considered too much.
How does vitamin D poisoning occur?
Vitamin D toxicity occurs when the amount of vitamin D in the body is too high to cause harm.
This condition is also known as hypervitaminosis D.
Vitamin D is a fat-soluble vitamin. Unlike water-soluble vitamins, it is very difficult for the body to remove fat-soluble vitamins.
Therefore, the excess can accumulate inside the body.
The exact mechanism that causes vitamin D poisoning is complex and so far we have not really understood it.
However, we already know how vitamin D works in the same way as steroid hormones.
Vitamin D moves in cells, signaling cells to activate or cancel genes.
Typically, most vitamin D in the body is stored, linked to vitamin D receptors or transport proteins. Very little vitamin D works "freely" .
However, too much vitamin D absorption will occur in cases where there is not enough room for vitamin D on transport receptors and proteins.
This can lead to an increase in "free" vitamin D levels in the body. These "free" vitamin Ds move in cells, causing the signaling process to overload.
One of the major signaling processes will help increase calcium absorption from the digestive system .
Therefore, the main symptom of vitamin D toxicity is - means that the amount of calcium in the blood increases .
High calcium levels can cause many different symptoms, and calcium can also bind to tissues including kidneys, causing damage to these tissues.
Conclude: Vitamin D poisoning is also known as hypervitaminosis D, which occurs when the amount of vitamin D in the body is so high that it causes harm, leading to hypercalcemia and other symptoms.
Vitamin D content in blood: Optimal and excessive
Vitamin D is an essential vitamin, and most cells in the body have its receptors .
This substance is created under the skin when the skin is exposed to the sun.
The main sources of vitamin D are fish liver oil and fatty fish.
For people who are not exposed to enough sunlight, they may need to take vitamin D supplements.
Vitamin D is very important for bone, immune function as well as anti-cancer protection .
Below are the standards for blood vitamin D levels :
- Just enough: 20-30 ng / ml equivalent to 50-75 nmol / Liter.
- Safety limit on: 60 ng / ml equals 150 nmol / L.
- The degree of toxicity: Over 150 ng / ml equals 375 nmol / L.
Drink 1000-4000 IU (25-100 micrograms) vitamin D every day It is just enough to make sure that blood levels of vitamin D are optimal in most people.
Conclude: The amount of vitamin D in the blood at about 20-30 ng / ml is considered sufficient. The highest safety limit is about 60 ng / ml, those with symptoms of toxicity are usually above 150 ng / ml.
How much is vitamin D?
Since we are not familiar with the mechanism of vitamin D toxicity, it is difficult to determine how much vitamin D is safe or toxic .
According to the Institute of Medicine, 4000 IU (100 micrograms) of vitamin D per day is the highest level of safety. However, no studies have demonstrated that doses of up to 10,000 IU (250 micrograms) are toxic to healthy people .
Vitamin D toxicity occurs due to excessive vitamin D supplementation, not by diet or exposure to the sun .
Although vitamin D toxicity is a rare occurrence, the current widespread use of supplements may lead to an increase in intoxication.
Drinking 40,000 to 100,000 IU (1000-2500 micrograms) of vitamin D daily for one to several months, has been confirmed to cause toxicity in humans .
This dose is 10-25 times higher than the upper limit recommended for regular dosing. People with vitamin D toxicity often have blood levels of vitamin D above 150 ng / ml (375 nmol / L).
There are some cases that occur due to a manufacturer's fault, when a supplement has a vitamin D content higher than 100-4000 times the amount printed on the packaging .
Blood levels of vitamin D in these cases ranged from 257-620 ng / ml, equivalent to 644-1549 nmol / L.
Vitamin D toxicity can be cured, however severe conditions will lead to kidney failure and arterial calcification .
Conclude: The upper safety limit of vitamin D is 4000 IU / day. Doses in the range of 40,000-100,000 IU / day (10-25 times the recommended upper limit) can cause toxicity in humans.
Symptoms and treatment of vitamin D poisoning
The consequences of vitamin D toxicity are mainly hypercalcaemia .
Early symptoms of hypercalcaemia include nausea, vomiting, diarrhea, constipation and weakness .
Frequent thirst (changes in sensation), high blood pressure, calcification in the kidney, kidney failure or hearing loss may also be symptoms of hypercalcaemia .
It takes months to treat hypercalcaemia due to the regular intake of high doses of vitamin D. The reason is that vitamin D accumulates in the body fat which is released into the blood very slowly .
Treatments for vitamin D toxicity include avoiding sun exposure and removing all vitamin D in the diet and supplements.
The doctor can also adjust the amount of calcium by increasing the amount of salt and liquid, saline transfer methods are often used.
Conclude: The main consequence of vitamin D toxicity is hypercalcaemia with symptoms of nausea, vomiting, weakness and kidney failure. The disease is treated by stopping the vitamin D intake into the body and not being exposed to the sun.
Using large doses can be harmful, even if there are no symptoms of toxicity
High doses of vitamin D can be harmful, but you will not experience symptoms immediately.
It seems that it takes months or even years for vitamin D poisoning symptoms to appear.
This is one of the reasons why vitamin D poisoning is so difficult to detect.
There have been cases of large doses of vitamin D for several months but no symptoms at all, but blood tests show hypercalcaemia and severe renal failure symptoms .
The effects of vitamin D are complex. High doses of vitamin D can cause hypercalcaemia without any symptoms of toxicity. But there is also the opposite case, symptoms of toxicity but not hypercalcaemia .
For safety, you should not exceed the limit of 4,000 IU (100 mcg) without consulting your doctor or dietitian.
Conclude: Vitamin D toxicity often develops over a long period of time with very complex consequences. Large doses may have a severe effect, although there are no noticeable symptoms.
Does taking fat-soluble vitamins change the tolerance of vitamin D?
It has been hypothesized that two fat-soluble vitamins, vitamin K and vitamin A, may play an important role in treating vitamin D toxicity.
Vitamin K helps control calcium in the body, and high levels of vitamin D can exhaust the amount of vitamin K stored in the body .
With higher amounts, vitamin A can prevent this by retaining stored vitamin K.
Magnesium is also an important nutrient. This is one of the substances needed to improve bone .
Taking vitamin A, vitamin K and magnesium and vitamin D can improve bone function and reduce the risk of calcification in tissues .
Remember that these are just hypotheses, but you should still provide them if you want to use a supplement containing vitamin D.
Conclude: Adequate intake of vitamin A, vitamin K and magnesium is very important if you are taking vitamin D supplements. These substances can reduce the risk of overcharging vitamin D into the body.
Things to remember
There are many ideas around high dose vitamin D supplementation. Therefore, it is difficult to assess which dose is safe and unsafe.
Vitamin D toxicity can cause serious health effects, but symptoms may take months, even years after starting high doses to appear.
In general, you should not use above the safety limit above 4000 IU (100 micrograms) per day.
Larger doses do not bring any health benefits, you do not need to use much.
High dose vitamin D is sometimes used to treat deficiency, but you must consult your doctor or dietitian before taking high doses.
Like many other nutrients, it's not always good to use too much.