Overdose of vitamin D is the most toxic of all vitamins. Supplements that contain two times the RDA for children and ten times the RDA for adults can produce vitamin D toxicity.
Excess vitamin D in the blood causes calcium to be deposited in organs such as the heart, kidney and brain.
Excess vitamin D will also contribute to, not prevent , osteoporosis and hardening of arteries and some studies shown that very high levels of vitamin D (around 80 ng/ml) can actually result in the same prostate cancer risk as vitamin D levels at are too low.
The initial signs of a vitamin D overdose are silent. It starts with an elevated calcium level in urine. And then there is an increase amount of calcium in the blood.
Symptoms of elevated calcium in the blood can include abdominal pain, constipation, muscle weakness, itching, vomiting, and extreme thirst.
However, it can never make too much vitamin D from sun exposure because excess vitamin D is automatically inactivated in the skin by further sun exposure. The Ultra violet B of vitamin D production is a self regulating process.
The synthesis of bioactive vitamin D hormone is tightly regulated and vitamin D toxicity usually occurs only if excessive doses are taken.
Toxicity of Vitamin D
