The Boston Bruins went south last week and added some Vitamin D to their game — as in “D”efense. It resulted in two wins and four points to keep their road record intact at a perfect 5-0-0 and their unbeaten streak at seven (6-0-1) with a pair of 3-1 wins over the Florida Panthers and Tampa Bay Lightning.

How would that play out Tuesday night against the current best in the West when the Dallas Stars came to Causeway Street? Legitimate contenders for a June parade, Dallas entered the game with two of the league’s top scorers in Jamie Benn (10-8-18) and Tyler Seguin (5-12-17) and newcomers Patrick Sharp and Johnny Oduya. The latter two drank from Lord Stanley’s Cup in June as Chicago Blackhawks.

Dallas dropped to 4-2 on the road after Monday night’s 4-1 stinker at Toronto.

Boston’s home record? Not even close where home cooking for the Black and Gold has produced little more than indigestion in their 1-4-1 log at TD Garden thus far. Here are a few things we learned off Tuesday’s decisive loss that means more than the 5-3 final score.

Fans need to pop the Tums for each home game:

Seguin notched his sixth goal in 12 games just 5:36 in when he and Benn and linemate Jason Spezza went 3-on-2 to beat Rask and take the early lead.

“We can’t allow them to have outnumbered situations,” Claude Julien said Tuesday morning about Dallas’ up-tempo offense.

The heartburn Bruins fans felt would get more intense as the game progressed.

Lucic trade starting to pay some dividends?

Colin Miller, one of the players that came to Beantown in the Milan Lucic trade, took a pass off the faceoff from Torey Krug just a minute and a half after Seguin’s goal, drilling a blue-line blast past Kari Lehtonen for 1-1 game. It was Miller’s first NHL goal and fourth consecutive game with a point; his plus-minus is a respectable plus-5 in 11 games.

That stat would drop back to plus-4 when Miller screened Tuukka Rask at 17:18 of the second period, while Jyrki Jokipakka whistled one from the left point past Rask for the go-ahead goal, 3-2.

The power play continues to sizzle while the penalty kill breaks down:

The Bruins entered the game with a league-leading 12 for 34 on the man advantage (35.3%).

Benn would take two at 19:20 and Loui Eriksson would need just 16 seconds to punch home the rebound of a Torey Krug rocket at 19:36 to put the Bruins up after the first period, outshooting the Stars overall, 15-6.

At the other end of the special-teams play, Boston’s penalty kill was 26th in the league.

“Every once in a while,” Julien said about the penalty-kill, “we have a tendency to shoot ourselves in the foot when making one bad mistake ends up in the back of the net.”

Seguin would do that in just five seconds when he knotted the score at 2-2 at 4:32 of the second period; Brett Connolly in the sin bin at 4:37.

Then Krug went to the box at 1:06 of the third period for too many men on the ice — and Dallas showed why they are a team on the quick rise. Seguin would complete his hat trick — good for the game’s No. 1 star — just 12 seconds later for the 4-2 lead with a left faceoff circle laser past Rask.

Dallas put this one to bed 10 minutes later when Brad Marchand went off for interference, and Alex Goligoski skated in solo on Rask lifting a backhander for the red light and the 5-3 final with Loui Eriksson scoring at 17:45 after Julien pulled Rask for the 6-on-4.

“We just kind of lost our focus and we weren’t the same team again,” Julien assessed. “Instead of trying to dig it in I think the way they were playing us our guys were getting more and more frustrated and the more we got frustrated, the more we got away from our game.”

What Chris Kelly’s injury means:

Just three seconds into his first shift of the night, veteran Chris Kelly’s season came to a crashing halt when he suffered a broken leg after falling backward. He will have surgery Wednesday morning.

“You hope we can somehow compensate for his loss,” Julien said postgame. “But I think people are going to realize how important he is to our hockey club, not just on the ice but also in the dressing room and around the team. He’s a guy that is extremely respected by his teammates. He was a very versatile player that we really counted on. No doubt he’ll be missed.”

The Rask task is getting serious:

Five goals allowed by Rask on 19 total shots does not bode well for the main man between the Bruins’ pipes.

“The truth is that I have to make more saves,” Rask said after. “I just wasn’t seeing the puck today.”

Following a week in which he allowed just one goal in his two starts, Rask took a big step back on Tuesday night.

”Star of the Week” almost star of the night:

Brad Marchand’s first shot of the night was highlight-reel worthy. The NHL’s No. 1 Star of the Week with nine points in his last six games — and two in each of his last six games — broke in clean on Lehtonen early in the second, deking but denied on the backhand by an equally highlight-reel skate save by the Stars’ goaltender.

Keep those Tums handy:

The Bruins’ home record dropped to a lowly 1-4-1.

In this season of early road comfort, the Bruins head back out to Washington, Montreal and Brooklyn the next five days.

“First period I didn’t mind,” Julien said, “and second period and third period, I don’t know where our team went.”

They went south.

But so far this week, not geographically speaking.