The Hidden Side Effects Of Taking Too Much Vitamin D

Vitamin D is an essential nutrient, and in an ideal world, we would get all that we need from our diet and from soaking up a little sun. But the combination of modern diets and religious use of sunscreen has left many of us with a Vitamin D deficiency. Lacking this vitamin can lead to depression, and has been linked to diabetes and even some types of cancer. Meanwhile, getting a healthy dose of this nutrient can help us absorb calcium, can promote better mental health, and helps ward off everything from high blood pressure to cancer (via WebMD).

No wonder doctors have been increasingly recommending supplements for those of us low on Vitamin D. But what is the proper dose, and how much is too much? Well, there are two types of Vitamin D you can supplement with: D2 and D3. D2 is the type that naturally occurs in plants, while D3 is the type our bodies make in response to sun exposure. D3 is much better at increasing blood levels of Vitamin D, and so this is the most commonly recommended. While the FDA's recommended intake of this nutrient is 200 IU a day up to the age of 50, 400 IU from 51 to 70, and 600 IU over age 70, many studies and experts say higher doses are needed to maintain optimal blood levels of the nutrient in those with a history of deficiency, and often doctors will recommend taking between 500-1000 IU per day (via Healthline).

Dangers of too much Vitamin D

But what are the effects of taking high doses of Vitamin D over a long period of time? Doctors say a health vitamin D blood level is 30 ng/ml (75 nmol/l), and the Vitamin D Council recommends maintaining levels of 40–80 ng/ml (100–200 nmol/l). However, blood levels over 100 ng/ml (250 nmol/l) may be harmful and can even be considered toxic. In the event that you are taking high doses of Vitamin D, you should make sure your blood is checked regularly by your doctor to ensure your levels are not exceeding what is healthy and safe (via Healthline).

Symptoms of Vitamin D toxicity include higher-than-normal calcium levels or "hypercalcemia," which can cause digestive upset, vomiting, nausea, and stomach pain along with fatigue, dizziness, confusion, excessive thirst, and frequent urination (via Insider). Longterm or severely toxic levels of Vitamin D can even lead to bone loss and kidney failure. It is, therefore, essential that your doctor keep an eye on your blood work while you are taking higher doses of vitamin D.