Have asthma? Spend some time in the sun

I N SUSCEPTIBLE people, asthma — which killed 17-year-old Akkriti Bhatia — can be triggered by fac tors ranging from indoor allergens (dust mites in bedding, carpets and stuffed furniture), outdoor aller gens (dust, pollution, pollens and mould), tobacco smoke, cold air, extreme emotion (anger or fear), and physical exercise.

Add to this, medicinal triggers such as non-steroid anti-inflammatory drugs such as aspirin, and beta-blockers (used to treat high blood pressure, heart conditions and migraine), as well as lifestyle factors such as long working hours, erratic eating habits and shift work and you will not be surprised by the spike in asthma attacks in susceptible people.

A chronic breathing disorder, asthma is characterised by recurrent attacks of breathlessness and wheezing. In India, over 20 million people have asthma, with children and people over 65 years being at higher risk of acute attacks.

One way to reduce severity suggests , new research from the Harvard Medical School, is to have adequate amounts of vitamin D, insufficient amounts of which appear to aggravate asthma and allergy severity The study suggests that .

giving supplements to asthma patients with Vitamin D deficiency may help control symptoms better.

The study — which will appear in the May issue of the American Journal of Respiratory and Critical Care Medicine— linked low serum levels of vitamin D in children with several indicators of allergy and asthma severity including , hospitalisation for asthma, use of inhaled steroids and total IgE levels (used to detect allergy).

The study found that children with lower vitamin D levels were hospitalised more often for asthma over the previous year, had airways with increased hyper-reactivity and used more inhaled , corticosteroids, all signifying higher asthma severity. These children also had several markers of allergy includ , ing dust-mite sensitivity .

Earlier studies had shown that people who don’t get enough sunlight and have diets low in vitamin D are at higher risk of osteoporosis (brittle bones) and developing colon, prostate, rectal, ovarian and breast cancers.

Fat-soluble vitamin D helps maintain the calcium and phosphorus absorption in the blood. It also helps in calcium absorption, which explains why its deficiency makes bones brittle or misshapen.

Apart from being present in fatty fish (salmon, mackeral, tuna, sardine) and fish oils (cod liver oil, shark liver oil), the vitamin is mainly synthesised under the skin under the effect of sunlight.

Since as much as 90 per cent of Vitamin D is produced under exposure to sunlight, the general impression was that its deficiency can be rectified easily by getting enough sun exposure.

Wrong. It seems most people living in sunny India are not out enough to make sufficient Vitamin D.

A study in Osteoporosis International last year reported that Indians need more sunlight than fairer Caucasians to synthesise the vitamin because of higher skin pigmentation. Increased time spent indoors, use of sunscreen and sun-protective clothing all lead to decreased levels of vitamin D.

So, how much Vitamin D do we need? The minimum recommended intake is 200 international units (IU) daily for children and young adults, 400 IU for those ages 51 to 70 and 600 IU for 71 years and older. To get 400 IU of Vitamin D, you have to have 200 gm of oily fish or a multivitamin every day .

It’s easier to make your own Vitamin D by exposing the skin to the sun: half an hour without sunscreen, as dark skin takes more time to make the sunshine vitamin. Try it, and breathe easy .

S A N C H I TA S H A R M A

sanchitasharma@hindustantimes.com