According to doctors and nutritionists vitamins are a very important part of human diet. Without vitamins the human body cannot function properly and it becomes prone to different types of diseases and infections. However when consuming vitamins one should be careful not to take too much of a certain vitamin because although they are extremely good and necessary for our health they can be toxic as well. As every other vitamin, vitamin D can cause side effects if taken in large amounts. Vitamin D is beneficial for the bones and teeth and the immune system. It also plays an important role in stimulating anti-tumor activity and maintaining the health of the kidneys. However people who take large doses of vitamin D may develop condition called hypervitaminosis D. This condition can be very serious but it can be successfully treated.
How Do People Become Vitamin D Overdosed
Vitamin D overdose is rare but people who suffer liver or kidney conditions as well as hyperparathyroidism may develop hypervitaminosis D. Sunlight is the primary source of vitamin D but the human body is capable of shutting down the natural production of vitamin D so prolonged sunlight exposure can’t lead to toxicity. Foods rich in vitamin D do not contain such large doses of it and are almost never the cause of hypervitaminosis D. Now you may guess that vitamin D toxicity can be caused by an excessive intake of vitamin D supplements. The human body doesn’t release vitamin D and it is being stored in the fat cells. When the body absorbs extremely large amounts of vitamin D, overdose happens.
Symptoms and Signs of Vitamin D Overdose
Depending on the metabolism, the vitamin D overdose symptoms can vary from one person to another. The most common symptoms of vitamin D overdose are:
- Weakness in the muscles
- Nausea and vomiting
- Lack of appetite and severe weight loss
- Constipation
- High blood pressure
- Polyuria (excessive production of urine)
- Kidney stones
- High urine and blood calcium
- Bone pain and even bone loss
- Polydipsia (increased thirst)
- Nervousness
- Severe headache
- Abdominal cramps
- Pruritus (itch)
- Hypercalcemia. Signs of hypercalcemia are fatigue, headaches, dry mouth, insomnia, mood changes, ringing in the ears and dizziness.
- Blindness
- Deafness
Vitamin D overdose is particularly dangerous for pregnant women because it can cause mental or physical defects in babies.
Steps That Should Be Taken If You Suspect Vitamin D Overdose
If you suspect that you may be suffering from vitamin D toxicity, you should stop supplementation and visit your doctor. Your doctor can determine if you are toxic by testing your 25(OH) D levels. People whose levels are lower than 200-250 ng/mL (500-750 nmol/L) are not overdosed. Hypervitaminosis D is sometimes mistaken for hypercalcemia which is caused by hyperparathyroidism and in some cases by sarcodosis and some cancers. People who suffer from vitamin D toxicity should avoid supplements containing vitamin D and even foods that contain this vitamin. It is recommended to drink at least 8 glasses of water daily and to avoid direct sun exposure and calcium intake. Hypervitaminosis D is successfully treated in most cases. But if one’s body has remained in a hypercalcemic state for too long permanent damage is possible since the calcium crystals are deposited in organs such are the heart, lungs and kidneys.
How Can Hypervitaminosis D Be Avoided
Recommended dietary allowances for vitamin D are:
- Babies up to 12 months can take 10 mcg of vitamin D
- Children and adolescents from 1 to 18 can take 15 mcg of vitamin D
- Adults from 19 to 50 can take 15 mcg of vitamin D
- Adults from 51 to 70 can take 15 mcg of vitamin D
- Adults over 70 can take 20 mcg of vitamin D
The adults shouldn’t take more than 4 mcg of vitamin D per day. People who take supplements should talk to their physicians before start using them.