6 side effects if you take too much vitamin D

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Vitamin D plays a role in keeping the body's cells healthy and working in the right direction. Most of us don't get enough vitamin D, so supplements are essential and common. However, if you add too much, it will make vitamin D accumulate and be toxic to the body. This article will talk about 6 potential side effects of excess vitamin D.

1.Deficiency and toxicity

Vitamin D is involved in calcium absorption, immune function, and protection of bone, muscle, and heart health. It occurs naturally in foods and can also be produced by the body when the skin is exposed to sunlight. Most people don't get enough sun exposure to produce enough vitamin D. Therefore, vitamin D deficiency is relatively common. In fact, an estimated 1 billion people worldwide are vitamin D deficient.
Both vitamin D2 and vitamin D3 can be taken in supplement form. Vitamin D3 is produced in response to sunlight and is found in animal products, while vitamin D2 is commonly found in plants. Vitamin D3 can increase blood levels significantly more than D2. Studies have shown that an average of 100 IU of vitamin D3 supplements that you consume each day increases your blood vitamin D levels by 1 ng/ml (2.5mmol/l), on average. However, Taking high doses of vitamin D3 for a long time can lead to an excessive accumulation in the body leading to an excess of vitamin d3. Vitamin D toxicity occurs when blood levels rise above 150 ng/ml (375 mol/l). Because vitamins are stored in body fat and released into the bloodstream slowly. As a result, the effects of toxicity can last for several months after you stop using the supplement. Importantly, toxicity is uncommon and occurs almost exclusively in people taking high-dose, long-term supplements without monitoring blood levels. You can also unknowingly consume too much vitamin D by taking a much higher amount than is listed on the label. Here are 6 major side effects of too much vitamin D.

2. High blood concentration

Adequate levels of vitamin D in the blood will help boost immunity and protect you from diseases like osteoporosis and cancer. However, there is not an optimal range for coverage.
Although a vitamin D level of 30 ng/ml (75mmol/l) is generally considered adequate, it is recommended to maintain a vitamin D level of 40 - 80ml (100 - 200mmol/l). Vitamin D levels above 100 ng/ml (250 mmol/l) can be harmful.
More and more people are taking vitamin D supplements. But it's rare to see people with very high blood levels of this vitamin. A recent study looked at data from more than 20,000 people over a 10-year period. Research has shown that only 37 people have levels above 100 ng/ml (250mmol/l). Only one had true toxicity, at 364 ng/ml (899 mmol/l).
In one case study, one woman had a level of 476 ng/ml (1,171nmol/l) after taking 186,900 IU of vitamin D3 daily for two months. This is a whopping 47 times the generally recommended safe upper limit of 4,000 IU per day. This woman was admitted to the hospital after she experienced fatigue, forgetfulness, nausea, vomiting, slurred speech, and other symptoms.
Although only extremely large doses can cause rapid toxicity, even strong advocates of these supplements recommend limiting them above 10,000 IU per day.

3. High blood calcium levels

Vitamin D helps your body absorb calcium from the foods you eat. In fact, this is one of its most important roles. However, with an excessive amount of vitamin D, blood calcium can reach levels that cause uncomfortable and potentially dangerous symptoms. Signs of too much vitamin D in the blood, or high blood calcium levels, include:
Digestive disturbances, such as vomiting, nausea and stomach pain Fatigue, dizziness and confusion Thirst Frequent urination regularly The normal range of blood calcium is 8.5 -10.2 mg/dl (2.1 .22.5 mmol/l). In one case study, an elderly man with dementia who received 50,000 IU of vitamin D daily for 6 months was repeatedly hospitalized with symptoms related to high calcium levels. In another case, two men took improperly labeled vitamin D supplements, resulting in blood calcium levels of 13.2 -15 mg/dl (3.3 -3.7). mmol/l). Furthermore, it took a year for their levels to normalize after they stopped taking the supplement.

4.Nausea, vomiting and poor appetite

Many of the side effects of vitamin D overdose are related to increased blood calcium levels. These include nausea, vomiting, and poor appetite. However, these symptoms do not occur in everyone with elevated calcium levels.
One study followed 10 people who developed excessive calcium levels after they took high doses of vitamin D to correct the deficiency. Four of them experienced nausea and vomiting and three of them lost their appetite. Similar reactions to vitamin D have been reported in other studies. One woman experienced nausea and weight loss after taking a supplement that was found to contain 78 times more vitamin D than the amount stated on the label.
Importantly, these symptoms occur when extremely high doses of vitamin D3 are taken, resulting in calcium levels greater than 12 mg/dl (3.0 mmol/l).

5. Stomach pain, constipation or diarrhea

Upset stomach , constipation and diarrhea are gastrointestinal side effects commonly associated with food intolerances or irritable bowel syndrome . However, they can also be a sign of elevated calcium levels due to vitamin D toxicity.
These symptoms can occur in people who take high doses of vitamin D supplements to correct a deficiency. As with other symptoms, the response appeared to be individualized even with similarly elevated blood levels of vitamin D. In one case study, a boy developed stomach pain and constipation after taking improper vitamin D supplements, while his brother developed high blood pressure without any other symptoms.
In another case study, an 18-month-old child given 50,000 IU of vitamin D3 for 3 months experienced diarrhea, stomach pain, and other symptoms. These symptoms ended after the child stopped taking the supplement

6. Osteoporosis

Because vitamin D plays an important role in calcium absorption and bone metabolism, getting enough is important to maintain strong bones. However, too much vitamin D can be detrimental to bone health. Although many symptoms of excessive vitamin D are attributed to high blood calcium levels, some researchers suggest that high doses of Vitamin D may lead to low blood levels of vitamin K2. One of the most important functions of vitamin K2 is to keep calcium in the bones and out of the blood. It is believed that very high vitamin D levels can decrease the activity of vitamin K2. To protect against osteoporosis, avoid excessive vitamin D supplements and supplement with vitamin K2. You can also eat foods rich in vitamin K2, such as dairy and grass-fed meat.

7. Kidney failure

Taking too much vitamin D regularly leads to kidney injury. In one case study, a man hospitalized with kidney failure had elevated blood calcium levels and other symptoms that occurred after he received a vitamin D injection prescribed by his doctor. Indeed, most studies have reported moderate to severe kidney injury in individuals with vitamin D toxicity. In one study in 62 people who received excessively high doses of vitamin D, all had signs of kidney failure, whether they had healthy kidneys or had existing kidney disease. Renal failure is treated with oral or intravenous hydration and medication.
Vitamin D is extremely important for overall health. Even if you follow a healthy diet, you may still need to supplement to get optimal levels. Make sure to avoid overdosing on vitamin D. In general, 4,000 IU or less per day is considered safe, as long as your blood is monitored.
Also, make sure you buy supplements from reputable manufacturers to reduce the risk of overdose from using the wrong label. If you take vitamin D supplements and experience any of the symptoms listed in this article, consult a healthcare professional as soon as possible.
Customers can directly go to Vinmec Health system nationwide to visit or contact the hotline here for support.
Reference source: healthline.com