Vitamin D Side Effects

The term 'vitamins' refers to the group of organic substances that are essential for the healthy functioning of the human body. There are 13 essential vitamins and each one of them plays a vital role when it comes to helping us attain optimal health. These are classified into fat-soluble and water-soluble vitamins. Vitamin D is one of these essential nutrients. It aids in the absorption of calcium and strengthens our bones. Since our body naturally synthesizes this vitamin when we are exposed to sunlight, it is also known as the sunshine vitamin. Foods that contain this vitamin include sardines, mackerel, eel, herring, egg yolks, cooked beef, liver, cod liver oil and certain types of mushrooms. As is the case with all vitamins, our body also needs the sunshine vitamin. However, one must understand that an overdose or a deficiency of this vitamin can have serious repercussions on one's health. Moderation is the key to good health which is why one must take this vitamin as per the recommended dietary allowance. This will help in preventing vitamin D side effects. In this article, we will find out about the common side effects due to an overdose or a deficiency along with ways to prevent such side effects.

RDA for Vitamin D

As mentioned earlier, vitamin D is a fat-soluble vitamin. Unlike the water-soluble vitamins that are absorbed into the bloodstream, the fat-soluble vitamins are stored by the fatty tissue of the body. When the intake of water-soluble vitamins is more than what the body needs, these are flushed out by way of urine. This minimizes the risk of vitamin toxicity. This doesn't hold true for the fat-soluble vitamins. Since these are stored by the body, overdosing on them can give rise to certain side effects. One must therefore comply with the guidelines regarding dosage. Earlier, the recommended dietary allowance of this vitamin was about 5 micrograms or 200 international units. However, with the rising cases of deficiency of this vitamin, medical experts are conducting research to ascertain the right daily dose. Researchers state that the recommended dietary allowance of this vitamin must be about 400 I.U. per day, with the daily tolerable upper intake level being 1000 I.U. for infants. Researchers believe that adults who are below the age of 70 years and growing children can take about 600 I.U. per day. However, a single dose which is beyond the tolerable upper limit of 4000 I.U., or intake of high doses for a prolonged time period of time can also give rise to certain side effects.

Researchers also believe that factors such as age and physical health must be taken into account while deciding the RDA. Adults, especially those who have crossed the age of 70 years, may need a higher dose. As we age, our body's ability to synthesize this vitamin from sunlight declines. Thus, elderly people must either take supplements or foods fortified with this vitamin to meet their body's requirement. The daily RDA for elderly people is about 800 I.U., while the tolerable upper intake limit is 4000 I.U., that is 100 micrograms. Side effects are most likely to be experienced by those who don't include the dietary sources of this vitamin to their diet. Those who don't get adequate sunlight or don't consume foods rich in this vitamin may experience distressing symptoms on account of this vitamin deficiency. At times, a deficiency may result from the inability of the digestive tract to absorb this vitamin. Since liver or kidney diseases impact the ability of the body to convert it to an active form, people suffering from such ailments might exhibit symptoms of this deficiency.

Side Effects

Since facilitates absorption of calcium and helps in maintaining normal level of calcium and phosphorus in blood, an overdose of this vitamin is most likely to lead to calcification of soft tissues in our body. This may make one susceptible to kidney stones. Besides the formation of kidney stones, an overdose could also lead to excessive production of urine. Taking high doses could lead to nocturia, which is a medical condition characterized by the need to get up many times at night to pass urine. Increased levels of calcium in blood (hypercalcemia) is one of the most common side effects. Those suffering from hypercalcemia usually experience symptoms such as excessive thirst, nausea, weak muscles, muscle cramps, pain in the abdomen, confusion or lethargy. An overdose could also make one prone to heart ailments or high blood pressure. Loss of appetite, nausea, vomiting, constipation, bone pain, insomnia or frequent urination are some of the problems that may occur due to an overdose.

Deficiency of the sunshine vitamin can trigger a wide range of health problems. In children, it can lead to rickets. Rickets is a disease that is typically characterized by bone deformities. On the other hand, adults suffering from this deficiency are prone to osteomalacia, which is a condition that is characterized by the weakening of the muscles and bones. It may cause pain in bones, muscles and joints. Obesity, skin pigmentation or inflammatory bowel disease can also be attributed to a deficiency. Deficiency can also hamper the production of insulin in the body, thereby making one susceptible to type 2 diabetes. As this vitamin also affects the working of our nervous system, a deficiency can trigger psychological problems such as depression or schizophrenia. It is believed that deficiency of this vitamin can also cause seasonal affective disorder (SAD). Also referred to as seasonal depression, SAD is a condition wherein one may feel depressed especially when winter approaches. However, the symptoms of seasonal depression can be alleviated by taking supplements. Light therapy may also be recommended for people who have been diagnosed with SAD.

Excess of anything is bad which is why people who are taking these supplements must adhere to the prescribed dosage. It would be best to fulfill the body's requirements by either including dietary sources of vitamin D to your diet or by getting the much-needed supply of sunshine vitamin by spending some time outdoors, basking in the sun.