What steel serves in the construction of a building, vitamin D serves the same in the human body, thereby giving strength and confidence to the individual. Along with calcium and phosphorus, vitamin D forms the basic core structure of the body, namely bones and teeth. Vitamin D we consume is in inactive form which needs to be converted into the active form in the kidneys before it is used by the tissues of the bodies.

   In this article you will find answers to commonly asked questions, like: What is the role of vitamin D in human body? What are the food sources of vitamin D? What is the daily requirement of vitamin D in children and in adults? What are the deficiency symptoms of vitamin D?

Activation of Vitamin D from Sunlight



ROLE OF VITAMIN D IN THE BODY

• Growth and Development of Bones: Everyone is equivocal regarding the role of vitamin D in normal development of bones. In fact, the very discovery of vitamin D was the result of the efforts to find out the lacking dietary factor which caused rickets in children.

• Absorption of Calcium from the Intestine into the Blood: Dietary calcium requires vitamin D to be absorbed into the circulation after it reaches intestine via food.

• Normal development of teeth: Risk of dental cavities and caries increases significantly with low vitamin D levels and it reduces dramatically with Vitamin D supplements

• Immunity: There is enough evidence to show the role of vitamin D in chronic debilitating infections like tuberculosis. Its role in respiratory, cutaneous, urinary or other infections is inconclusive.

• Mood Elevation: Vitamin D has shown mild to moderate effect in allaying the symptoms of depression, especially in SAD (seasonal affective disorder). Researchers have found that those who commit suicide had significantly lower levels of vitamin D in their blood!

WHO IS AT THE RISK OF DEVELOPING VITAMIN D DEFICIENCY?

• People with Excessively Dark Skin:
Dark skinned people have less ability to produce vitamin D due to the presence of a pigment called melanin in their skin which acts as a natural filter to ultraviolet rays and thereby prevent the formation of vitamin D under the skin.

• People who are Exposed to Bad Radiation:
Just like there is bad cholesterol and good cholesterol, there is bad radiation and good radiation, too. Good radiation comes from natural sunlight and bad or harmful radiation comes from computer screens, mobiles, mobile towers, wifi routers etc. Good radiation has a protective effect on the growth of the bones while the bad radiation has a detrimental effect.

• People who are Deprived of Sunlight:
People who are chronically bedridden, people who work indoors, people who prefer to cover their whole body with clothing or sunscreens and people who reside at higher latitudes like those in Norway, Greenland, Argentina, Chile or New Zealand.

• People with Chronic Liver or Kidney Diseases:
Vitamin deficiency occurs because liver and kidney are needed to convert the inactive form of vitamin D into the active form. See the diagram above.

• Breastfed Babies of Vitamin D Deficient Mothers

DEFICIENCY SYMPTOMS OF VITAMIN D

The incidence of vitamin D deficiency is increased in the 21st century where 50% of the population is deficient in vitamin D. Vitamin D deficiency can go undetected for several years until the patient is advised to get a blood test done by his physician.

• In Children:
Deficiency of vitamin D in childhood is characterized by the impeded growth of bones causing their softening and bending giving rise to bow legs, a condition called rickets.

• In Middle Aged:
I) Easy fatigue and low stamina with inability to concentrate on work
ii) Chronic neck pain and lower back pain
iii) Lack of interest and depressed mood especially in winter
iv) Vague muscular aches, pains and cramps
v) Repeated dental problems like caries and
brittleness of teeth
vi) Chronic knee pain

• In the Elderly:
Vitamin D deficiency results in osteomalacia which is characterized by thinning, malformation and brittleness of bones. Such bones are prone to easy fractures. This condition could be corrected, although the treatment can last for several weeks to months.

 • In Post-Menopausal Women:
Increased risk of osteoporosis which could be prevented by taking vitamin D with calcium and estrogen supplements

Daily Requirements:
In health: 600 IU/day (15 mcg)
In deficiency states: 1000 IU/day (25 mcg)

Note: Unlike vitamin C, vitamin D supplements do not alter the outcome for blood pressure, diabetes, coronary artery disease, myocardial infarction, stroke, cerebrovascular disease, cancer, knee osteoarthritis etc, as the evidence from various studies is inconclusive and inconsistent to draw strong conclusions in this matter, though vitamin D supplements are widely marketed for their claims about their role in protection against these disorders. Vitamin D may have a beneficial effect in preventing atherosclerosis by promoting the deposition of calcium in bones rather than in the blood vessels.


            Top Ten Sources of Vitamin D

Best Food Sources of Vitamin D

 Read more: Vitamin A, Vitamin B12, Vitamin C, Vitamin E




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