Stocks remained in the red Tuesday as crude oil traded at its lowest level in more than a week. 

The S&P 500 was down 0.25%, and the Nasdaq slid 0.39%. The Dow Jones Industrial Average briefly turned positive before returning to the flatline. 

Crude oil sold off on Monday as Iran made clear it wouldn't participate in negotiations with the Organization of Petroleum Exporting Countries next week. Hopes had been high that OPEC members and non-member Russia could agree upon a production freeze in the face of tumbling oil prices but are unlikely to do so unless all countries are on board.

"Unless Iran has an unexpected change of heart, their current position effectively ends the prospect of OPEC coordination in the short-term," said Robbie Fraser, commodity analyst at Schneider Electric. "As a result, any OPEC-related premium that contributed to oil's rise throughout much of 2016 is likely being returned."

West Texas Intermediate crude oil closed 2.3% lower at $36.34 a barrel on Tuesday, its lowest close since March 4. 

The energy sector was one of the worst performers Tuesday. Major oilers including Royal Dutch Shell (RDS.A - Get Report) , Chevron (CVX - Get Report) , Total (TOT - Get Report)  and BP (BP - Get Report) fell, while the Energy Select Sector SPDR ETF (XLE - Get Report) slid 0.8%.

Valeant Pharmaceuticals (VRX)  pulled the health care sector into a selloff. The company tanked 50% after sharply downgrading its outlook. The drugmaker expects first-quarter earnings no higher than $1.55 a share, well below previous guidance of $2.35 to $2.55 a share. Valeant said weakness was tied to softer demand for its gastrointestinal drugs.

Valeant shares have fallen 32% since the beginning of the year, hit hard at the end of February after withdrawing its guidance. The company is also currently under investigation from U.S. authorities over its distribution models.

Fellow drugmakers such as Pfizer (PFE - Get Report) , Eli Lilly (LLY - Get Report) , Gilead (GILD - Get Report)  and Celgene (CELG - Get Report) slid, while the Health Care Select Sector SPDR ETF (XLV - Get Report) slumped 1.5%. 

Homebuilder confidence remained unchanged in March with opinions on current conditions remaining steady, though sales forecasts in the next six months looked more challenging. The National Association of Home Builders' housing market index was flat at 58 in March. Economists had expected the metric to tick up to 59. Any reading above 50 points to expansion.

U.S. retail sales in February fell for the second straight month, dragged down by increased discounts at car dealerships and lower gas prices. Retail sales fell 0.1%, in line with estimates. Excluding energy and autos, retail sales were flat from a month earlier. Worryingly, January sales were revised downward to show a 0.4% dip.

"The sharp downward revision to January's estimates suggests that the momentum at the start of the year was far weaker than previously thought," Millan Mulraine, deputy chief U.S. macro strategist at TD Securities, wrote in a note. "Nevertheless, with labor market activity remaining buoyant and household's mood relatively upbeat, we expect spending momentum to rebound in the coming months as U.S. household spending continue to underpin the economic recovery."

Weaker retail sales prompted Barclays to cut its first-quarter U.S. economic growth forecast to 1.9% from 2.4%. Fourth-quarter GDP rose 1%.

Energy prices continued to be a major drag on producer prices. The Producer Price Index in February fell 0.2%, as economists had expected. Excluding food and energy, core prices rose 0.1%.

Business inventories in January came in at a higher ratio than expected as U.S. companies struggled to sell what they have produced. The ratio of inventories to sales inched to 1.40, higher than a reading of 1.39 in December.

Economic activity in the New York region improved for the first time in eight months in March. General business conditions recovered to a reading of 0.6, according to the Empire state Manufacturing Survey, far better than negative 16.6 in February.

The Federal Reserve will convene for a two-day meeting on Tuesday morning, concluding with a statement and press conference Wednesday afternoon. The majority of economists don't expect the Fed to increase interest rates at this meeting after raising them in December for the first time since they were reduced to nearly zero during the 2008 financial crisis.

What will be more important, however, is how the Fed frames its future plans. Members had previously forecast four rate hikes this year at the end of 2015, but that looks less likely after a string of disappointing manufacturing data in the first quarter. 

Avon Products (AVP - Get Report) fell 7% after announcing 2,500 job cuts and a headquarters move to Great Britain from New York. The cosmetics company recently sold its North American business to private-equity firm Cerberus.

HD Supply Holdings (HDS - Get Report) climbed 5% after swinging to a profit in its recent quarter thanks to strong sales demand across its product lines. First-quarter guidance also came in stronger than expected with an earnings range of 45 cents to 50 cents a share topping forecasts of 44 cents.

Darden Restaurants (DRI - Get Report) fell after activist investor Starboard Value trimmed its investment, selling another 1.3 million shares to reduce its stake to 5.2%. The firm held a 9.1% stake at the beginning of the year.

3D Systems (DDD - Get Report) tumbled 12% after JPMorgan downgraded the stock to underweight from neutral with a $10 price target. Analysts said the company has limited sales visibility.