Vitamins are nutrients that the body requires on a regular basis in limited amounts. They are organic compounds that the body primarily obtains by means of the food that it consumes. But one vitamin that is present in the body but cannot be obtained in adequate quantities in our diet is Vitamin D. It is a fat-soluble vitamin that is not sufficiently available to the body from our diet as it has limited sources and is primarily produced by the body on exposure to sunlight with the help of cholesterol in the body.
Although different organisations differ in the amount of Vitamin D that the body requires, the general volumes range from 600 IU per day for people ranging from 1 to 70 years, 800 IU for people over 70 years and 400 IU for infants. For those who are unable to meet the body’s needs of this vitamin with adequate exposure to sunlight, another means of meeting the requirements is to take supplements.
The role of Vitamin D is essential for absorption of important minerals by the body like iron, calcium, magnesium, phosphate and zinc. It has been found to have a positive effect on muscle and brain development, cardiovascular function as well as respiratory function. Increased immune function is also another benefit attributed to this vitamin. Some studies have also linked the presence of this vitamin in reducing incidences of cancer, depression and dementia.
• Promotes Muscle Function: A literature review conducted at Tufts University in Boston by Rachele Pojednic and Lisa Ceglia indicated that decreased levels of Vitamin D in the body is linked to decreased capacity to sustain aerobic activity in individuals along with a higher BMI or body fat ratio. This vitamin is known to positively affect muscle strength, size and performance. It also reduces the cases of weak or deformed bones as well as muscle inflammation, thus promoting normal muscle functioning.
• Increases Testosterone Production: The effect of Vitamin D in testosterone production has been documented only in laboratory results at this stage. In an experiment conducted by Austrian scientists, isolated human testes tissue showed an increased testosterone production on addition of Vitamin D along with stimulators of testosterone production like luteinizing hormone and Insulin-linked growth factor (IGF-1).
• Reduction in Cases of Obesity: A study at the University of South Dakota has linked Vitamin D and calcium to increased cell apoptosis or cell death, thus promoting fat cell management. In the study, mice fed Vitamin D and calcium rich diets showed improved fat metabolism markers along with decreased body fat and better sugar regulation in their bodies. Although the long term effects of this are still unknown, the positive effect of this vitamin on fat cell management has been encouraging.
One of the major drawbacks of having insufficient amounts of Vitamin D in the body is weak or deformed bones, leading to conditions like rickets and osteoporosis. Thus, it is particularly important to maintain sufficient vitamin levels in those who are either aged with weaker bones or those with high performance and energy requirements like sportsmen and bodybuilders.
The overall performance in high energy and high fitness like sports persons and weight lifters is likely to be affected by low levels of this vitamin in the body. There is also the risk of adverse effects in cases involving the elderly. While reduced calcium absorption resulting in weak and brittle bones can in turn result in fractures and broken bones, the presence of weak muscles can affect everyday functioning and overall performance of the individuals. In the elderly, there is a risk of a fall due to muscle weakness, with additional fear of broken or fractured bones.
Apart from having weaker bones and deteriorated muscle control, low levels of Vitamin D in the body has in a research at the University of Louisiana by a team headed by Laura Forney been linked to low fitness levels and increased incidences of obesity in college students. These students, who had Vitamin D deficiency with level below 250 HD were reported to have low aerobic capacity along with increased body mass indexes. A literature review done by Pamela von Hurst and Kathryn Beck from Massey University in New Zealand reported similar findings. Along with this, in the former study the students were observed to have reduced physical activity and impaired athletic performances.
Another major problem associated with this vitamin’s deficiency in men is that of enlarged prostates in affected individuals. A range of other conditions like incontinence, frequent, sudden and strained urination as well as incomplete emptying of the bladder usually accompany this enlargement. This problem is commonly seen in about half the men over 50 years and 80 per cent men over 80. Geovanni Espinosa from the New York University School of Medicine has documented this occurrence in a literature review. Vitamin D supplements can help manage the deficiency linked prostate enlargement. No documented side effects observed on the use of these supplements can be of great use in such cases of ageing men.