Make “D” while the Sun shines
The common saying – “Make hay while the sun shines” is now
applicable for Vitamin D also. Vit.D is an essential nutrient which performs a
wide variety of vital functions in our body. Historically (I think from the
time it was discovered that human skin can make Vit.D from sun rays), it has
been believed that Indians have been able to synthesize adequate amounts of
Vit.D but recent researches have proved this to be a disbelief. Ideally, thirty
minutes of exposure of the skin over the arms and face to sunlight, without the application of
sunscreen, preferably between 10 am to 2 pm (as maximum ultraviolet B rays are
transmitted during this time) daily is adequate to avoid Vit. D deficiency.
India, located between 8.4 and 37.61 N latitude, is a vast
tropical and warm country. Most of the Indian regions receive ample amount of
sunlight throughout the year. Also being a agricultural and a rural country,
most of the people spend time outdoors in the sun, so the time exposed to the sunlight
is quite high. Earlier, Vit.D deficiency
was considered to be disease of west, since the amount of exposure to sunlight
among the western countries is very less. Surprisingly, recent researches have shown
that there has been an increase in the incidence of Vit.D deficiency among
Indians as well.
There may be various reasons for us developing this
deficiency inspite of the widespread availability of sunlight in our country.:
Ø
Darker skin pigmentation and the changes which have
accompanied India’s modernization, including increased hours spent working
indoors and pollution, limit sun exposure for many.
Ø
Changing food fads and food habits contribute to low
dietary calcium and Vit. D intake;
Ø
High fibre diet containing phosphorus and phytates which
can deplete Vit. D stores and increase calcium requirement;
Ø
Genetic factors like having increased 25(OH)D-24-hydroxylase
which degrades 25(OH)D to inactive metabolites;
Ø
It has been shown that increment in serum 25(OH)D in
response to treatment depends on the heritability of Vit. D binding protein;
Ø
Increased pollution may also hamper the synthesis of Vit.
D in the skin;
Ø
Repeated, unspaced and unplanned pregnancies in already
deficient patients may aggravate Vit. D deficiency in both the mother and the
foetus.
Earlier Vit.D deficiency was only thought to be present in children of lower socio-economic status but now the picture seems to be changing. The nutrient deficiency is now being commonly found in otherwise healthy children and adults. Deficiency of Vit.D at such a small age may hamper appropriate
growth and development since childhood resulting in a clinical condition termed as rickets whereas in adults it may lead to an early onset of osteo-porosis. However, the vitamin now has been shown to
play a variety of roles ranging from an anti-oxidant to that being a
anti-cancer nutrient.
Its been a high time now to open our eyes to a problem which was probably long standing but we recognized it quite late. According to a estimate by WHO, approximately one billion people in world have Vit.D deficiency.
Until fairly recently, Vit. D deficiency in children has
been observed in essentially every country in the world. It affects a large
proportion of population, irrespective of age and sex. The reason for delay in
recognition is perhaps Vit. D is the most under-rated nutrient in the world of
nutrition probably because it’s “free”. But the truth is, unawareness as most
people don’t know the real story of Vit. D and health.
No comments:
Post a Comment