Body in Motion / Fitness for Life  / The ‘Sunshine Vitamin’

The ‘Sunshine Vitamin’

Yes, that’s what it is also called. Vitamin D. While there is some growing awareness about this Vitamin, knowledge about its functions and the role it plays in maintaining health is still poor.


It’s important to first understand what Vitamins are in general.

Vitamins are organic compounds needed in small quantities by the body to power and sustain life. We source them externally from the food we eat and supplements, because the human body does not either produce them or does so inadequate measure.

They are of two types:

Fat soluble Vitamins – Are stored in fat tissues of the body and the liver, where they reside as reserves for longer time.

Water Soluble Vitamins – These are not stored in the body for a long period and get expelled through urine.

Vitamin D belongs to the first category. In more scientific terms, it belongs to a group of fat soluble secosteroids (subclass of steroids) which is produced endogenously (within an organism, tissue or cell).


A major role of this Vitamin is in maintaining bone health. We are commonly aware that Calcium is needed for bone strength. Vitamin D helps in the absorption of calcium (and phosphorous) important for building strong, healthy bones.

It blocks the release of parathyroid hormone which reabsorbs bone tissue causing them to become thin and brittle.

Vitamin D plays a role in maintaining muscle function and building the immune system. It helps keep illnesses and infections under control and has also been shown to reduce risk of falling in older people (which could be attributed to possibly better muscle control along with stronger bone health).

While the debate is still out there regarding the extent, studies suggest Vitamin D might play a positive role to help prevent conditions like cancers (breasts, colon, prostate) heart disease, diabetes, high blood pressure and multiple sclerosis. (Empirical evidence is still being evaluated).

Studies are also evaluating its positive role in addressing conditions like depression, weight gain, autism, autoimmune disorders, neuromuscular diseases etc.


Sun exposure – Our bodies produce vitamin D when the skin is exposed to direct sunlight. (Hence the name “Sunshine Vitamin”). Direct exposure refers to pre sunscreen exposure. Not too much though, considering excess sun exposure can increase risk of skin cancer and aging, since it’s the ultra violet light in sunlight that causes skin to make Vitamin D. Between five -15 minutes of direct sun exposure is general recommendation. The presence of a pigment called ‘Melanin’ in the skin determines how much Vitamin D one can produce. Darker skinned people with high melanin content produce less since more melanin allows less UV rays to penetrate the skin. They may need longer exposure than fair skinned people. Other factors affecting how much sun exposure is needed includes time of day and climate. The sun’s rays are stronger and sharper (more intense) at noon than early morning and evening. Colder clime people need more exposure to the sun to produce Vitamin D in adequate amount. It would also get affected by pollution, cloud cover and where one lives (closer or farther away from the equator) and age (older people have harder time producing Vitamin D).

Food (Diet)

– Small amounts of Vitamin D come from foods naturally containing the nutrient or fortified with it. These include fatty fish, liver, egg yolks, cheese, fortified milk and orange juice, fortified cereals and fortified yogurt. Dietary sources may sometimes not be consumed in enough measure to provide adequate vitamin D to fulfill the body’s requirement.


– To be consumed as recommended by your doctor and depending upon the level of deficiency. Usually Vit D3 and Calcium supplements are prescribed after running tests. It’s prudent and safer to seek professional advice than consuming these over the counter to ensure that the requisite dose is ingested. Overdosing is as much a possibility as not taking enough and can give rise to unpleasant symptoms. Additionally, there are certain health conditions and medications that can contribute to Vit D deficiency. Your doctor would take all these into consideration before prescribing a supplement and it’s dosage.


The amount of vitamin D you need each day depends on your age. Average daily recommended amounts from the Food and Nutrition Board (a national group of experts) for different ages are listed below in International Units (IU):

Life Stage Recommended AmountBirth to 12 months 400 IUChildren 1–13 years 600 IUTeens 14–18 years 600 IUAdults 19–70 years 600 IUAdults 71 years and older 800 IUPregnant and breastfeeding women 600 IU

** Reproduced from

Different sites give slightly varying recommendations. But this seems to be a ballpark figure.SYMPTOMS OF VITAMIN D DEFICIENCY.

Most of the times Vitamin D deficiency goes unnoticed. Bone pain, muscle weakness or spasms, frequent fractures, constant fatigue and soft bones are some of the common symptoms. Severe deficiency can lead to Rickets (a condition found in children characterized by bone softening and skeletal deformities), secondary hyperthyroidism, osteopenia, osteomalacia and osteoporosis.

Most times the symptoms are mild and overlooked. The best way to detect for deficiency, as mentioned, is a diagnostic blood test. The preferred one on account of better accuracy is called the 25-hydroxyvitaminD, written as 25(OH)D.


Eating more foods that contain Vitamin D.

Adequate exposure to direct sunlight.

Using supplements as required and recommended.


Given the role VITAMIN D plays in maintaining health, especially bone health and muscle function, the importance of maintaining it in adequate levels for athletes should be interesting to evaluate. The primary focus of an athlete is performance – both in terms of activity and recovery. Strong and healthy bones would be an essential requirement for athletic pursuits. The greater the demands on the body, the greater the need of a strong, stable structure. Additionally, good muscle recovery would enhance performance and reduce stress. Thus, Vitamin D would appear to be a positive contributor towards the twin goals of athletic performance and injury prevention. Whether one runs, or plays any other sport, the physiological benefits of Vitamin D and it’s role as an ally deserves a deeper look.

+ Long term research is awaited. The article does not aim to make a case of prescribing Vitamin D as a prevention protocol for these conditions. This is to simply highlight the thought trend and that there may be more to Vitamin D than currently meets the eye as a gate-keeper to better health and fitness.


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