Urbanisation cuts people off adequate sunlight

Washington, Feb 17 (IANS) Increasing urbanisation is cutting off people from adequate sunlight, which helps the skin produce vitamin D, facilitating the absorption of calcium, says a study.

About two million years ago, permanent dark skin colour imparted by the pigment -- melanin -- began to evolve in humans to regulate the body's reaction to ultraviolet rays from the sun, said Nina Jablonski, professor of anthropology at Penn State University.

Melanin helped humans maintain the delicate balance between too much sunlight and not enough sunlight.

The pigment allowed enough ultraviolet radiation to produce vitamin D, while protecting the skin from the intense ultraviolet radiation in the equator. Too much sunlight can cause the destruction of folate, which is also critical to cell division.

Unlike their ancestors, modern humans are more mobile. "We move around a lot now," said Jablonski.

"People can move across 90 degrees of latitude in a single day whereas early humans generally only went a few kilometres in the same time."

Most people now live in cities with limited exposure to the sun. Nearly 60 percent of world's people live in cities now, she said.

Most of these people indoors, further reducing their ability to make enough vitamin D in their skin, according to Penn statement.

"Think about a farmer who lived in northern England and worked outside," said Jablonski.

"In the past, that farmer had the right amount of light pigmentation to make it possible for him to produce enough vitamin D in his skin in the summer to satisfy most of his yearly needs."

However, Jablonski said a typical worker who lives in England today is rarely exposed to that amount of sun, which only compounds health problems.

"This can lead to a vitamin D catastrophe for many people," Jablonski added.

These finding were presented at the at the annual meeting of the American Association for the Advancement of Science in Boston.

Matches

MORE TOP STORIES TODAY

Srinivasan named in fixing report: SC

Srinivasan named in fixing report: SC

The court emphasised that the tainted administrator can no longer work for the BCCI. More »

On-field action set to divert from off-field drama

On-field action set to divert from off-field drama

The Preview — Defending champions Mumbai Indians take on Kolkata Knight Riders More »

Why I'm not looking forward to the IPL

Why I'm not looking forward to the IPL

Welcome to another season of a league that many watch but few trust. More »

'If you do the wrong thing it will be found out'

'If you do the wrong thing it will be found out'

'Everyone knows what is right and what is wrong and if you do the wrong thing it will be found out' More »

Mitchell Johnson may quit T20s for Test cricket

Mitchell Johnson may quit T20s for Test cricket

Australia's Mitchell Johnson may quit limited-overs cricket to prolong his test career with an eye on the 2015 Ashes series in England, the fast bowler… More »

Srinivasan appeals to court to allow BCCI comeback

Srinivasan appeals to court to allow BCCI comeback

He was aggrieved by the allegations against him during the hearing. More »

There's a lot going on: Fleming

There's a lot going on: Fleming

He experienced anxious moments in the lead-up to the tournament as the courts decided on whether to suspend the franchise, he said, but stressed that the… More »

Latif couldn’t work with tainted players

Latif couldn’t work with tainted players

Former Pakistan cricket captain Rashid Latif said Tuesday he turned down the job of national chief selector because he could not work with ex-players tainted… More »

We are not over-confident: Bailey

We are not over-confident: Bailey

Indian Premier League — George Bailey-led Kings XI Punjab will face Chennai Super Kings on Friday. More »

Taxing issue — BCCI hits roadblock

Taxing issue — BCCI hits roadblock

MoU between BCCI & its units to avoid double taxation delayed after a few decline to share details. More »

Big runs expected, with bat and ball

Big runs expected, with bat and ball

Royal Challengers Bangalore: Their main concern, once again, is the fast bowling More »

Black Caps pick rookie duo for West Indies

Black Caps pick rookie duo for West Indies

New Zealand selectors included two new caps in a 15-man Test squad named Tuesday to tour the West Indies, with injury-hit spinner Dan Vettori's future… More »

India: cricket's Brazil

India: cricket's Brazil

They are tough to beat with a big talent base exposed to good facilities. (CYCSPL) More »

Delhi Daredevils say no to gifts

Delhi Daredevils say no to gifts

Franchises are doing their bit to refurbish the image of the tainted league. More »

Klinger on his exit from South Australia

Klinger on his exit from South Australia

Michael Klinger has revealed he felt compelled to leave South Australia after being told he would be only a fringe part of the Redbacks' plans for next season, and disputed the suggestion that he left… More »

India-Pakistan Test series likely in 2015

India-Pakistan Test series likely in 2015

The revival of Indo-Pak Test ties could take place in UAE. More »

Kohli hopes to end RCB trophy drought

Kohli hopes to end RCB trophy drought

'This time around we will hope to go few more steps ahead and actually get that trophy' More »

Gavaskar can help IPL regain glory

Gavaskar can help IPL regain glory

Apart from the foreign players a lot of behind-the-scene activity has taken place in selecting the Indian domestic players. More »

Tendulkar, Ganguly to promote soccer

Tendulkar, Ganguly to promote soccer

Leading Spanish club Atletico Madrid and former cricketers Sachin Tendulkar and Sourav Ganguly are among the owners of eight franchises of a new Indian… More »

This isn’t my first trip to India: Neesham

This isn’t my first trip to India: Neesham

Kiwi all-rounder wants to utilise the India leg to explore the country’s tourist attractions. More »

Ishant wanted to quit ODIs

Ishant wanted to quit ODIs

Says his mother made him change his mind. More »

Supreme Court says no to BCCI’s request

Supreme Court says no to BCCI’s request

Bench refuses to grant access to recordings of Srini and Dhoni’s depositions before Mudgal committee. More »

Pietersen’s ‘little’ secret is out

Pietersen’s ‘little’ secret is out

A fractured little finger could now throw the Delhi Daredevils captain out of action at the start of this season. More »

SMA Trophy gets short-changed

SMA Trophy gets short-changed

Key players are away preparing for the IPL, taking the shine off the other domestic T20 fixture. (CYCSPL) More »