Vitamin D, popularly known as the ‘sunshine vitamin’ is very much needed by the human body. It makes the bones stronger and healthy. But an overdose of this vitamin can lead to Vitamin D toxicity or hypervitaminosis D! This results in an abnormal increase in calcium levels in the blood. And this condition is known as hypercalcemea, which leads to many severe ailments.
Vitamin D is not an essential dietary vitamin as it can be synthesized in adequate quantity by humans when exposed to sunlight.
Sources Of Vitamin D:
Apart from sunlight, there are many foods that are loaded with Vitamin D. This is a fat soluble vitamin, which makes it mandatory to consume fat for its absorption.
- Fatty fish, fish oils, egg yolks, beef liver, some kind of mushrooms and cheese contain high amount of Vitamin D.
- The human body can synthesize Vitamin D in the skin when exposed to adequate sunlight.
- Low calorie fortified breakfast cereal like Multi grain Cheerios has enough Vitamin D content.
- For vegetarians, mushrooms can be a perfect source of Vitamin D. Preferably, Portobello mushrooms and white button mushrooms contain Vitamin D in more quantity.
- Dairy products, such as milk, cheese, yogurt and butter have adequate amounts of Vitamin D.
- Fortified soy products, such as tofu and soy milk also contain high amount of Vitamin D.
- Red and black caviar and oysters are also the recommended sources of Vitamin D.
- Cod liver oil is known as the most popular Vitamin D supplement.
- Other products like fortified orange juice and chocolate malt drink mixes also contain this vitamin.
- Egg is another amazing and widely available source of Vitamin D. Egg yolks are loaded with Vitamin D, but they are also high in cholesterol content. So are not usually recommended.
Side Effects And Health Risks Of Vitamin D Consumption:
Vitamin D toxicity is not caused by overexposure to sun or food. It is the result of consuming heavy doses of Vitamin D supplements. Our body manages to regulate the quantity of Vitamin D produced by sun exposure. And food does not contain such high quantities of Vitamin D even if they are fortified. But, if you consume a too much of Vitamin D, you might experience the following side effects:
1. Hypervitaminosis D:
Though rare, this is one of the most serious health risks of Vitamin D overdose. One of the major side effects of Vitamin D overdose is that it increases the calcium level in the blood. This condition is also called hypercalcemia. It results in loss of appetite, nausea, weakness, urinary and kidney problems.
2. Worsens Kidney Condition:
Individuals who have liver or kidney conditions are at a greater risk of Vitamin D toxicity. So, take vitamin supplements only in consultation with a doctor.
3. Increases Cholesterol Level:
Vitamin D-rich foods, such as eggs, salami, cheese, whole milk, caviar and oysters are also high in cholesterol. It is important that these are consumed in moderate amounts.
You may experience various symptoms due to Vitamin D toxicity. Some of the symptoms include headache, dry mouth, drowsiness, constipation, confusion, muscle or bone pain, weakness, loss of interest in sex, change in behavior, feeling irritable, fainting, pain in the stomach and metallic taste in the mouth.
5. Not Suitable For Heart Patients:
Individuals with heart diseases or stroke should abstain from Vitamin D-rich food. Excessive consumption of Vitamin D supplement can lead to risks of heart attack, heart arrhythmias or abnormal heart rhythm.
6. Allergic Reactions:
Vitamin D overdose can also cause allergic reaction in some people. Immediate medical help may be required in case of symptoms of any of the allergic reactions as difficulty in breathing, swelling of the lips, tongue, throat or face.
7. Can Cause Kidney Stones:
Intake of excessive Vitamin D supplements may lead to polyuria and kidney stones
8. Can Lead to Digestive Issues:
Some other symptoms of Vitamin D toxicity may include dehydration, vomiting, fatigue, muscular weakness and metastatic calcification of the soft tissues.
9. Can Cause High Blood Pressure:
Excessive intake of Vitamin D can cause over calcification of heart and kidney. It can also lead to hypertension in extreme cases.
10. Other Side Effects:
Overdose of Vitamin D may also be responsible for symptoms like high levels of phosphate, calcium and protein in urine, urinating more than usual, ringing sensation in the ears, shortness of breath, seizure and vertigo.
Recommended Vitamin D Supplement Limits:
The US Institute of Medicine has detailed a tolerable upper level of Vitamin D supplement intake to protect against vitamin D toxicity.
- 0 to 6 months: 25 µg (1000 IU)
- 7 to12 months: 38 µg (1500 IU)
- 1 to 3 years: 63 µg (2500 IU)
- 4 to8 years: 75 µg (3000 IU)
- 9+ years: 100 µg (4000 IU)
- Pregnant and lactating females: 100 µg (4000 IU)
- The recommended dietary allowance: 15 µg /d (600 IU per day).
- Overdose: 1,925 µg / d (77,000 IU per day).
- Acute Overdose: 15,000 µg / d (600,000 IU per day) and 42,000 µg / d (1,68,000 IU per day) taken for over a period of many days to months.
- Safe level intake: 250 µg / d (10,000 IU per day).
Treatment For Vitamin D Toxicity:
The doctor may prescribe the following treatments, if you are suffering from Vitamin D toxicity:
- Discontinuation of Vitamin D supplements immediately.
- Temporarily lowering the intake of dietary calcium.
- Use of corticosteroids or bisphosphonates to suppress the release of calcium from bones.
- Monitoring of Vitamin D levels until it reverts back to normalcy.
A Word Of Caution:
It is advisable to see your doctor immediately on experiencing any symptoms of hypervitaminosis D. While there are many symptoms associated with vitamin D toxicity, the most commonly associated conditions includes excessive thirst, polyuria which lead to frequent urination and high blood pressure.
The doctor may advise the following pathological tests if you suffer Vitamin D toxicity:
- Blood tests to check levels of Vitamin D, calcium and phosphorus.
- A urine test to determine excessive amount of calcium in the urine.
- X rays of bones to determine the intensity of bone loss.
Just because something is good for our body does not mean we need to binge on it! Our body needs limited amounts of Vitamin D. So, make sure you include Vitamin D supplements only under medical supervision.
Do you know of any other Vitamin D side effects? Share with us in the comments section below.