Vitamin D Toxicity & Its Impact on Health
If you take excessive supplements or prescription vitamin D, it can lead to vitamin D toxicity. The major complication of this is moderate to severe hypercalcemia. This issue can further give rise to symptoms like increased thirst, vomiting, and frequent urination, and can even affect multiple organs.
What is Vitamin D Toxicity?
Vitamin D toxicity or hypervitaminosis D occurs when you have too much vitamin D in your body. It is somewhat of a rare complication that generally happens from taking higher-than-prescribed amounts of prescription Vitamin D or too much of a self-prescribed over-the-counter supplement.
Vitamin D toxicity disease generally is not life-threatening, but it can be quite harmful to your health. Severe or major cases can cause issues like abnormal heart rhythm, kidney failure, unsteady gait and confusion.
What Does Vitamin D Mean?
Vitamin D is an essential vitamin that your body uses for normal bone development and to maintain your bones. Vitamin D also plays a crucial role in your musculoskeletal system, nervous system, and immune system. Your body converts the vitamin D that you consume into the active form of vitamin D.
This active form helps your body absorb calcium. You can also get Vitamin D in multiple ways, including sun exposure, through nutritional supplements, and through the food and drinks you consume. Vitamin D toxicity only happens from taking too much of a supplement or prescription medication.
What Causes Vitamin D Toxicity?
Vitamin D intoxication is mainly caused by taking large doses of Vitamin D supplements. You are not likely to get this disease from eating the foods that naturally contain Vitamin D. This list includes fish, egg yolks, and some mushrooms. Even items with added vitamin D, like cow's milk, don't contain huge amounts of vitamin D. Here are some major reasons this disease occurs among individuals.
- Using over-the-counter supplements in amounts higher than recommended by health experts.
- Accidentally consuming multiple supplements containing vitamin D.
- Prescription dosing errors.
- Taking large doses for an extended period without assessing blood levels.
It is necessary to note that vitamin D toxicity is not caused by excessive sunlight exposure. Our body naturally regulates the amount of vitamin D produced through sunlight while preventing dangerous accumulation.
Who is at Higher Risk of Vitamin D Toxicity?
Although anyone taking excessive supplements can develop vitamin D toxicosis, certain individuals might have a higher risk, as mentioned below.
- Older adults taking multiple nutritional supplements.
- People self-medicating with high-dose supplements.
- Individuals getting long-term vitamin D therapy.
- Children who accidentally consume adult supplements.
- Patients with certain medical conditions needing vitamin D supplementation without proper assessment.
Regular blood tests can help reduce the risk in people taking prescribed vitamin D.
What are the Vitamin D Toxicity Symptoms?
The Vitamin D toxicity symptoms mainly occur because high vitamin D causes calcium levels in your bloodstream to rise.
Here are the most prominent vitamin D intoxication symptoms you should be aware of:
- Nausea: Many individuals experience continuous nausea as one of the earliest signs of Vitamin D toxicity. It might occur after meals or throughout the day and can affectyour appetite.
- Poor Appetite: Excessive calcium can interfere with normal digestive function, causing a noticeable loss of appetite. Eating less over time might also contribute to weakness and weight loss.
- Stomach Pain: Abdominal pain or cramping might occur because of digestive disturbances caused by Hypercalcemia. The discomfort can range from mild to severe.
- Constipation: High calcium levels can slow down your bowel movements, making constipation a common symptom. Some individuals might also experience bloating and abdominal discomfort.
- Frequent Urination: As the body tries to eliminate excessive calcium, urination becomes more frequent. If fluids are not replaced, dehydration can develop quickly.
- Excessive Thirst: The kidneys work harder to remove excessive calcium from the body, while increasing the fluid loss. This often makes affected individuals feel unusually thirsty throughout the day.
- Fatigue: High calcium levels can interfere with normal muscle and nerve function, causing persistent tiredness. Even after adequate rest, many people continue to feel exhausted.
What are the Risk Factors Included in Vitamin D Toxicity?
People who take prescription-strength vitamin D are at risk for toxicity of Vitamin D3. This is due to the high dose of the medication unless they verify their levels periodically. Certain conditions require high doses of vitamin D. Some of the most common are listed here.
- Osteoporosis
- Renal Osteodystrophy
- Osteomalacia
- Psoriasis
- Gastric bypass surgery
- Inflammatory bowel disease
- Celiac disease
- Multiple sclerosis
How is Vitamin D Toxicity Diagnosed?
Doctors diagnose Vitamin D toxicity by assessing your symptoms, supplement intake, medical history, and laboratory tests. Here are some common investigations to look into.
- Vitamin D blood tests
- Blood calcium levels
- Kidney function tests
- Urine calcium tests
- Blood phosphate levels
If kidney risks are suspected, imaging tests might also be recommended to detect kidney stones or calcium deposits. Early diagnosis can help you prevent long-term complications.
Management and Treatment of Vitamin D Toxicity
Vitamin D toxicity treatment mainly includes lowering the level of calcium in your blood.
- To do this, a healthcare practitioner will make you stop taking all vitamin D and calcium supplements until further notice.
- They might give you IV fluids to treat dehydration.
- They can also give you corticosteroids and bisphosphonates in cases of serious toxicity to block bone resorption.
In riskier or rare cases, due to significant kidney damage, you might require hemodialysis to get rid of excessive calcium.
How Much Vitamin D is Too Much?
Upper limits for vitamin D include the amount you get from your total intake, including your dietary sources and vitamin D supplements. According to the National Institutes of Health, the upper limit for daily vitamin D intake by age group is listed here.
| Age Group | UL |
| 0–6 months | 25 mcg/day (1,000 IU) |
| 7–12 months | 38 mcg/day (1,500 IU) |
| 1–3 years | 63 mcg/day (2,500 IU) |
| 4–8 years | 75 mcg/day (3,000 IU) |
| ≥9 years | 100 mcg/day (4,000 IU) |
Managing Vitamin D Intake for Better Health
Although vitamin D toxicity is uncommon, it can become more serious if excessive supplements are taken without proper assessment. As symptoms often develop gradually, many people might not recognise the condition until calcium levels become dangerously high.
Reader Information: This article is for educational purposes only and should not replace professional medical advice. If you suspect vitamin D toxicity or experience symptoms of hypercalcaemia, consult a qualified healthcare professional promptly.
