A century ago, Vitamin D hit the limelight to combat a disease known as rickets. Lack of Vitamin D results in the inadequate absorption and regulation of calcium and phosphates causing permanent bone deformities in children. An estimate of one billion of the world's population suffers from Vitamin D deficiency as doctors are again diagnosing the comeback of rickets.  

According to data published in the Journal of American Medical Association (JAMA), 18% of the American populace is in an overdose level of Vitamin D while 3.2 % are at a precarious dosage of the supplements. The Sunshine is also a source of Vitamin D and exposing our skin to the rays of the sun produces it in our body. The food we eat can provide us with vitamin D like milk, cereals, orange juice, fatty fish and other supplements.

An overdose of Vitamin D has its dangers that people should be wary of. One of the major effects of Vitamin D excess is Bone Calcification. This effect causes pain around the bone making it brittle and prone to fractures and skeletal injuries. Dehydration is also an effect of the deficiency. Increased levels of calcium trigger the body to flush out excess Vitamin D making those trips to the bathroom more frequent. Heart problems are also prevalent among excess Vitamin D sufferers. The overdose of this vitamin makes people weak, have episodes of confusion and lack of focus, reports Healthline.

Other symptoms of Vitamin D Excess are fatigue, loss of appetite, weight loss, excessive thirst, constipation, irritability, tinnitus or ringing of the ear, dizziness, nausea, and high blood pressure. Too much of Vitamin D determinable by blood testing. Results of blood test with over 150 ng/ml measuring 25(OH)D is at toxic levels. Vitamin D intake of 10,000 IU/day is an overdose that needs to be looked over by a physician, reports Vitamin D Council.

To prevent such overdosage of Vitamin D, a limit has been set at 4,000 IU/day. Doctors recommend adding calcium-rich foods in the diet like cod liver oil, fatty fish (salmon or tuna), some mushrooms, egg yolks, beef liver, and cheese.