Vitamin Focus: D

This article is the fourth in a series focusing on the different vitamins. Other vitamins that have already been covered are vitamin A, the B vitamins, and vitamin C.

What is vitamin D and what does it do for us? Primarily, vitamin D helps the body absorb and maintain the right amount of calcium and phosphorus in our blood. It also helps reduce inflammation and modulates neuromuscular and immune function.

What happens if we do not take in enough vitamin D? Vitamin D deficiency is associated with rickets and osteomalacia in children and adults, respectively. Rickets is characterized by softening of bones, which often leads to fractures or deformities. This same disease in adults is known as osteomalacia.

How much vitamin D should we take in? Can we take in too much? Most people need about 5 micrograms of vitamin D per day, but this amount should be increased to 10 micrograms per day for those 51 to 70, and increased again to 15 micrograms per day for those over 70. The amount also varies slightly based on gender. Too much vitamin D causes your body to absorb too much calcium in the bloodstream. This is called hypercalcemia.  Symptoms include nausea, vomiting, poor appetite, constipation, weakness, and kidney stones. However, vitamin D toxicity is rare and is generally a result of taking supplements, thus it can be “cured” simply by not taking the supplements. Another way to treat vitamin D toxicity is to increase one’s intake of fluids in order to dilute the amount in the bloodstream.

How can we get vitamin D? The body can manufacture vitamin D on its own and does so with exposure to sun. However, getting too much sun will not cause vitamin D toxicity, because your body only produces a limited amount in this manner. You need less than an hour’s worth of sunshine. Common sources of vitamin D are dairy products: cheese, butter, and cream. Fortified milk also contains vitamin D; all milk in the U.S. falls under this description. Outside of dairy products, you can also find it in fish, oysters, and fortified cereals.