Woman with headache and nausea

Can High Doses of Vitamin D Lead to Nausea? A Comprehensive Guide

Vitamin D, or sunshine vitamin, as some call it, is a requisite nutrient that helps our bodies absorb and maintain adequate calcium levels. It’s essential for bone health, bone strength, nerve functioning, the development of muscle cells, the proper functioning of the immune system, and more. 

Vitamin D is typically produced by the skin when exposed to the sun’s ultraviolet-B radiation (UVB), but you can also find it in certain vitamin supplements and some foods.

While a deficiency of this nutrient is a widespread problem, it’s also possible but rare to have a high vitamin D level in your system. Excess vitamin D, also known as vitamin D toxicity or hypervitaminosis D, can cause several unpleasant physical symptoms, including nausea.

Whether you’re a medical professional looking for information to share with your patients or someone with health conditions that may require higher doses and is interested in learning more about the potential side effects of vitamin D, this post is for you.

Here, we’ll delve into the nuances of vitamin D toxicity, exploring its prevalence, symptoms, and, most importantly, why excessive doses can induce nausea.

Let’s Jump in!

Understanding vitamin D toxicity

Vitamin D toxicity, also termed hypervitaminosis D, occurs when your body has an excess of vitamin D. It's a rare issue caused by taking higher than the prescribed amount of vitamin D supplement or too much of a self-prescribed over-the-counter (OTC) supplement.

High vitamin D levels in the blood induce hypercalcemia (higher-than-normal calcium levels in the blood), producing side effects.

Vitamin D toxicity is rarely fatal, but it can be pretty harmful to your health. 

Severe cases might result in kidney failure, arrhythmia (abnormal heart rhythm), confusion, unsteady gait (ataxia), and even death. It is unclear at what blood levels these effects occur.

Is vitamin D toxicity common?

Vitamin D toxicity is not common. Typically, you will have to take a lot of vitamin D daily for months before you start to have toxic effects.

According to reports by the Food and Nutrition Board, toxicity is most likely to appear when you have a daily intake of at least 10,000 IU (250 mcg).

However, if you are someone who needs to take the vitamin D supplement daily to prevent any side effects, it is best to do a Vitamin D test regularly. 

Regular test is also advised if you are hypersensitive to the vitamin, as normal vitamin D intake could constitute an overdose in these situations, resulting in outrageous blood calcium. 

Vitamin D intake will need to be reduced in these circumstances.

Speak with your doctor; they can help you determine an appropriate vitamin D dosage and monitor your intake to help prevent side effects.

Why do high doses of vitamin D lead to nausea?

With one in every four Americans having low vitamin D levels, it's no surprise that many people may consider taking a supplement, mainly since this crucial nutrient is found in very few foods. 

However, as we have established, vitamin D can have adverse effects, especially if taken in large quantities. 

This is because vitamin D is fat-soluble, so if taken in high doses, it can build up in the body's fat stores and potentially reach toxic levels. 

When vitamin D reaches this level, the main effect is increased blood calcium levels (hypercalcemia), often leading to nausea, vomiting, and other physical symptoms.

How do I stop nausea from high doses of vitamin D?

Nausea caused by high doses of vitamin D can be disconcerting. Here, we will tell you some simple steps to avoid it.

Adjust the amount of vitamin D to take each day

A person's hand holding an vitamin capsule in front of a window.

Everyone needs a certain amount daily, and the right amount varies by age. If you discover that you or your child have nausea that persists due to vitamin D intake, you may need to adjust your dosage. 

Gradually reduce the amount you’re taking, allowing your body to adjust to a more suitable level. 

Better still, ask your healthcare provider or your child’s pediatrician to review your supplementation history and provide personalized recommendations to address the nausea effectively.

Know how much calcium to take each day

Since Vitamin D toxicity is also linked to calcium intake, it is crucial to monitor your calcium intake. The IOM recommends a daily calcium dose of:

  • Children ages 1 to 3: 500 mg daily
  • Children ages 4 to 8: 800 mg daily
  • Children/teenagers age 9 to 18: 1,300 mg daily
  • Women ages 19 to 50: 800 mg daily
  • Women older than 50 years: 1,000 mg daily
  • Men up to 71 years old: 800 mg daily
  • Men 71 years and older: 1,000 mg daily

Again, excessive calcium supplementation alongside high doses of vitamin D may contribute to symptoms. Strive for a balanced approach to both nutrients.

Ensure adequate hydration

Hydration can help you recover from your nausea. Ensure you’re drinking enough water throughout the day, as dehydration can worsen feelings of nausea. 

Adequately hydrating supports overall well-being and can contribute to a more balanced response to vitamin D supplementation.

Take vitamin D with food

Consuming vitamin D supplements with meals can sometimes alleviate nausea. Food helps buffer the absorption of the vitamin and can minimize gastrointestinal discomfort. 

Consider taking your vitamin D supplement during or after a meal to enhance absorption and reduce the likelihood of nausea.

Keep all follow-up appointments.

If high doses of vitamin D are prescribed, keep all follow-up and lab appointments. 

Many of the amounts prescribed are enough to produce vitamin D toxicity that can lead to nausea and other more severe conditions like kidney or tissue damage, so regular blood tests to spot high levels of vitamin D or calcium are essential.

Read also: Can Vitamin D Cause Constipation? (Answered!).

What are other symptoms of vitamin D toxicity?

Besides nausea, high levels of vitamin D in your bloodstream can cause the following:

  • Decrease in appetite
  • Constipation
  • Dehydration
  • Increased thirst (polydipsia)
  • Frequent urination
  • Confusion and fatigue
  • Muscle weakness and difficulty walking
  • Bone pain
  • Kidney stones

Talk to your doctor if you suffer from any of the above symptoms. Tell them about the supplements, drugs, and substances you use and the amounts. 

If your doctor feels that your symptoms might be linked to an excess of vitamin D in your system, they may order lab tests to examine your blood serum levels.

Related reading: Understanding Vitamin D Deficiency Causes Symptoms and Remedies.

How to diagnose vitamin D toxicity

Healthcare professionals rely on the following to diagnose vitamin D toxicity:

  • Your symptoms.
  • A history of your medications and supplements.
  • Vitamin D blood tests.
  • A calcium blood test.
  • Kidney function tests.

Treatment of vitamin D toxicity

Treatment for vitamin D toxicity mainly involves lowering the calcium level in your blood.

To do this, your healthcare professional will:

  • Tell you to stop taking all vitamin D and calcium supplements until further notice.
  • Give you IV fluids to treat dehydration.
  • Give you corticosteroids and bisphosphonates (medications) in cases of severe toxicity to block bone resorption.

In rare cases, due to significant kidney damage, you may need hemodialysis to get rid of excessive calcium.

How to prevent vitamin D toxicity

There are some steps you can take to prevent vitamin D toxicity, including:

  • Consult your healthcare provider before starting a vitamin D supplement.
  • Do not take more than the prescribed vitamin D supplements your provider recommends.
  • If you take prescription vitamin D, ensure you get regular blood tests to monitor the vitamin D level in your blood.
  • Store your vitamin D supplements and prescriptions safely away from children and pets. And only buy supplements from a reliable, licensed source.

Need naturally made vitamin D supplement to boost your mood, heart and bones, and Immunity? Check out our Organic Vitamin D3 supplement. They are organic and can help you maintain your nutrient level without the risk of nausea.

What is the right amount of vitamin D to take daily?

A woman holding a glass of water and a vitamin.

Healthy daily requirements for vitamin D vary by age, as described below: 

  • The Endocrine Society recommends 1,500 to 2,000 IU of vitamin D daily for adults. 
  • Infants under one year old should get 400 to 1,000 IU daily, and children and adolescents should get 600 to 1,000 IU daily.
  • The Institute of Medicine suggests lower daily doses: 400 IU daily for children and adults and up to 800 IU daily for adults 71 years and older.

Both recommendations are well below the maximum safe daily dose of 4,000 IU. Either way, consult your healthcare provider if you’re concerned about your vitamin D intake. They can provide guidance based on lab results and guidelines.

Takeaway: Avoid high doses of vitamin D to avoid nausea

Many people take vitamin D supplements to help meet their daily requirements; however, too much vitamin D can cause several unpleasant physical symptoms, including nausea.

Avoid excessive doses of vitamin D. Generally, for people with adequate vitamin D levels, taking supplements of 4,000 IU or fewer per day is considered safe.

For those who may need to take high doses of the vitamin, taking monthly blood tests to assess vitamin D and calcium levels in your system will be necessary to minimize toxicity,

While vitamin D toxicity effects can range from mild physical symptoms like nausea to more serious conditions like kidney damage, it is an essential nutrient that is required for your body's proper functioning.

If you are on a vitamin D prescription but are worried about geting the right supplement, Why Not Natural offers high-quality, natural, and adequate vitamin D supplements that are free of preservatives or fillers, GMO-free, diabetic-friendly, and all common allergens. 

Get our vitamin D supplement today!

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