INSIGHTS AND PERSPECTIVES

DALLAS — Low levels of vitamin D have been linked to depression, according to UT Southwestern Medical Center psychiatrists working with the Cooper Center Longitudinal Study in a release issued Thursday.

This new study — published in Mayo Clinic Proceedings — helps clarify a debate that erupted after smaller studies produced conflicting results about the relationship between vitamin D and depression. Major depressive disorder affects nearly 1-in-10 adults in the United States.

WHAT IT MEANS AND WHY IT'S IMPORTANT — The fact that Wall Street is reversing its position on a breakup of CVS Caremark is important because — while we may hate to toot our own horn, we are going to do it anyway — DSN was right.

(THE NEWS: Wall Street analysts recant prediction of CVS Caremark split. For the full story, click here)

BOSTON — As many as 20% of smartphone users made a purchase after scanning a QR code, according to a Consumer Pulse study released Wednesday by Chadwick Martin Bailey and iModerate Research Technologies.

MINNEAPOLIS — Despite an overall decrease in free standing insert coupon activity, retailer promotion pages within the FSI vehicles recorded a 30.7% increase to more than 17 billion pages in 2011, continuing the significant annual increases in retailer promotion activity, which began in 2007, Kantar Media reported Wednesday.

Overall, the number of free-standing insert coupons distributed through 2011 dropped 6.5% compared with 2010. This decline in FSI coupon activity followed two consecutive years of annual increases of 8% in 2009 and 7.2% in 2010.

DARIEN, Ill. — A new study published in the recent issue of Sleep has found that young Type 1 diabetics may have difficulty controlling their blood-sugar levels due to lack of sleep.

WASHINGTON — The U.S. News & World Report on Wednesday named the top five "easiest" diets New Year's resolutionists should follow — Weight Watchers, Jenny Craig, Mediterranean Diet, Slim Fast and Volumetrics — out of a total field of 25 diet plans.

RESTON, Va. — The November-December 2011 holiday season marked a new record in retail e-commerce spending, ComScore reported.

The season realized an overall gain of 15% versus last year, totaling $37.2 billion. This record was achieved with help from ten individual shopping days that surpassed $1 billion in spending, led by Cyber Monday — which ranked No. 1 for the second consecutive year — at $1.25 billion.

CHICAGO — Thanks to a last-minute shopping rush, Christmas 2011 likely will outpace its prior-year counterpart. According to a report released Wednesday by ShopperTrak, consumers spent approximately $44 billion in retail sales for the week ended Dec. 24, a 37.8% increase over the previous week and a 14.8% gain over the same week last year.

Foot traffic also was high, increasing 32.4% from the previous week.

The last-minute sales increase ensured this December will outpace December 2010. Month-to-date figures are up 4.7% over December 2010.