Side Effects of Vitamin D

Vitamins are a group of nutrients that are required by the body in small amounts. Human beings require 13 types of vitamins that are broadly classified into water-soluble and fat-soluble forms. Vitamin D is a group of fat-soluble vitamins. The two major forms that are important for human beings are vitamin D₂ also known as ergocalciferol and vitamin D₃ which is also referred to as cholecalciferol. Together they are called the calciferols. Foods like fish, egg, cod liver oil, cheese buttermilk and fortified milk are rich sources of vitamin D. Although required in small amounts, it is important to maintain proper levels of vitamin D in the body, as a deficiency or overdose may lead to side effects of vitamin D.

Functions of Vitamin D
Although calcium and phosphorus are most important for healthy bones as they are what the bones are made up of, vitamin D plays a vital role in ensuring that these minerals are absorbed properly in the bones. Vitamin D helps the intestines to absorb calcium from the food that we eat, so that it can be used to strengthen the bones. Recent studies indicate that vitamin D helps in preventing osteoporosis, hypertension and cancer. Vitamin D is also believed to strengthen the immune system and help in proper functioning of the nervous system. However, more research is required in this direction.

Daily Requirements of Vitamin D
Vitamin D is required in very small amounts by the human body. Individuals aged between 1 to 50 years require a daily dose of 5 mcg. However, the daily requirement increases with age. Although vitamin D can be obtained from a number of dietary resources, sunshine is considered to be an important source of vitamin D. Exposure to sunlight for about 10 to 15 minutes thrice every week is enough to meet the body requirements for this vitamin. However, symptoms of vitamin D deficiency are often seen in people who live in tropical regions where plenty of sunlight is available.

Side Effects of Vitamin D
Vitamin D side effects can be broadly broken down into 2 categories, which are overdose and deficiency. Let us take a look at the side effects of both overdose and deficiency of vitamin D.

Overdose of Vitamin D
Overdose of vitamin D makes the intestines absorb too much calcium. As a result, levels of calcium in blood will increase. This will lead to the calcification of soft tissues in the body like the heart, lungs, blood vessels and renal tubules, that will impair their ability to function properly. High levels of vitamin D may also have a negative effect on the functioning of the renal system. This will be manifested in the form of polyuria, nocturia, polydipsia and renal failure.

Another symptom of vitamin D overdose include formation of kidney stones that may cause a lot of pain. Mental retardation, nausea, weakness of the muscles, muscle cramps, muscle atrophy, severe headache and nervousness are associated with high levels of vitamin D in the blood. In addition to these, overdose of vitamin D also makes one prone to high blood pressure and heart diseases.

Deficiency of Vitamin D
The two classic effects of vitamin D deficiency are rickets in children and osteoporosis in adults. Rickets causes the bones to become soft due to which they become more prone to fractures. It also causes deformity of the long bones. Although it can occur in adults, in most cases, rickets is found in children suffering from severe malnutrition.

In osteoporosis, the bone mineral density is reduced because of which the bones become weak and tend to get fractured easily. Although this is a very common problem in women after they reach menopause, men may also suffer from osteoporosis due to old age. Besides osteoporosis, low levels of vitamin D may cause osteomalacia in an adult which results in the weakening of muscles along with softening of the bones. Other symptoms of low vitamin D levels include insomnia, weight loss, pain in the bones and muscles and weakening of the immune system.

It is important to maintain proper intake of the sunshine vitamin in the body, as inappropriate levels will result in side effects of vitamin D. Taking a balanced diet can ensure the right amount of all nutrients in the body. Besides that, regular exercise and proper rest can also help one lead a healthy life.