New Delhi : Vitamin D is often called the “sunshine vitamin” and is widely recommended for strong bones, immunity, and overall well-being. In recent years, its use has increased sharply, especially after the pandemic, with many people taking supplements regularly without testing or medical advice.
While vitamin D deficiency can cause health problems, doctors caution that excessive intake can be just as harmful.
When taken in very high doses over time, vitamin D can raise calcium levels in the blood, a condition known as hypercalcaemia. This excess calcium puts enormous pressure on the kidneys, which are responsible for filtering waste from the body.
Over time, calcium can start depositing inside kidney tissue, leading to kidney stones, nephrocalcinosis, and even acute or permanent kidney failure. Recognising early symptoms of vitamin D overdose is crucial, as timely action can prevent long-term damage.
HOW VITAMIN D OVERDOSE AFFECTS THE KIDNEYS
Excess vitamin D forces the body to absorb more calcium than it needs. The kidneys must work harder to filter this excess calcium from the blood. Over time, calcium can build up inside the kidneys, forming stones or permanent deposits.
This condition, called nephrocalcinosis, damages the kidney’s filtering units and may lead to acute kidney injury or irreversible kidney failure if left untreated.
WHY DOES OVERDOSE OFTEN GO UNDETECTED?
Vitamin D overdose is often missed because early symptoms are vague and can be mistaken for common illnesses. Nausea, vomiting, fatigue, and confusion may not immediately raise suspicion.
Studies and case reports have shown that overdose can occur not only due to self-medication but also due to prescription or dispensing errors, especially when high-dose supplements are taken daily instead of weekly.
SIX SYMPTOMS OF VITAMIN D OVERDOSE TO WATCH OUT FOR
- Nausea and vomiting: High calcium levels irritate the stomach and digestive tract.
- Persistent thirst and frequent urination: The kidneys struggle to remove excess calcium, leading to dehydration.
- Muscle weakness and extreme fatigue: Elevated calcium interferes with normal muscle function.
- Confusion or poor concentration: The nervous system may be affected by an electrolyte imbalance.
- Lower back or side pain: This may signal kidney stones or kidney stress.
- Swelling in legs and breathing difficulty: In severe cases, kidney damage can cause fluid retention and shortness of breath, requiring urgent medical care.
HOW MUCH VITAMIN D IS SAFE FOR ADULTS?
According to health guidelines, most adults require about 400 to 1,000 IU of vitamin D daily. Regular intake above 4,000 IU per day can increase the risk of toxicity, especially if continued for months.
A common cause of overdose is mistakenly taking 60,000 IU capsules daily, even though they are meant for weekly use. Excess vitamin D raises blood calcium levels, which directly strains kidney function.
HOW TO PREVENT VITAMIN OVERDOSE
Doctors advise taking vitamin D supplements only under medical supervision. Blood tests should be done to check vitamin D and calcium levels before starting supplements and during long-term use.
Avoid combining multiple supplements that contain vitamin D, and never increase doses on your own. If symptoms such as vomiting, confusion, weakness, or frequent urination appear, medical help should be sought immediately.
Vitamin D plays an important role in keeping bones strong and immunity healthy, but more is not always better. Uncontrolled supplementation can quietly damage the kidneys and other organs.
Regular testing, proper dosing, and medical guidance are key to enjoying the benefits of vitamin D while avoiding serious and long-term health risks.
