Drug Fair, Inc., second largest of the Washington area's retail drug chains, yesterday reported a sharp decline in profits for the first three months of 1977. The company blamed extremely cold weather during January and February for the slump.

Bowl America, a Northern Virginia firm that operates bowling centers, also cited the bad weather as a factor in its depressed results.

Capital Mortgage Investments, meanwhile, posted a loss of $1.3 million for the first quarter - mainly because of additions to reserves for possible loan losses by the Chevy Chase real estate investment trust.

Earnings for Drug Fair in the quarter ended March 31 totaled $107,000 (6 cents a share) compared with $692,000 (39 cents) for the same period last year. Sales rose slightly to $52.5 million from $50.9 million.

Because of the recent decline, profits also were down for the first nine months of Drug Fair's fiscal year to $1.87 million (1.07) from $2.33 million 1.33). Sales for the three quarters rose to $171.6 million from $161.6 million.

According to Drug Fair, sales "rebounded strongly" during March after the January and February cold spell.

Capital Mortgage Investments said its $1.3 million loss in the first quarter contrasted with "a breakeven" operation in the same period last year. Revenues declined to $1.89 million from $1.92 million.

The recent loss reduced the Chevy Chase trust's net worth to about $331,000 from $2.8 million a year ago. CMI added $2.2 million to reserves for possible losses following re-evaluation of development prospects on two properties, the trust reported. Negotiations are continuing with 25 banks to extend and modify a $57.7 million credit agreement scheduled to expire June 1.

Equitable General Corp. of McLean, parent company of Equitable Life Insurance Co., reported profits before investment gains or losses of a record $2.6 million (81 cents a share) in the first quarter, up 18.5 per cent from $2.2 million (67 cents) in the 1976 period.

Sales of individual life policies totaled $50.8 million, a gain of 3 per cent from a year ago. President Charles E. Phillips said Equitable has purchased a 10.7-acre site in McLean on which it plans to construct a headquarters building. Directors also declared a dividend of 15 cents a share, payable June 1 to stockholders of record May 13.

Closing forced by the natural gas shortage last winter caused a slight dip in profits at Bowl America, Inc., but earnings rose at another bowling center company, Fair Lanes, Inc., in the third quarter ended with March.

Bowl America, based in Northern Virginia, reported profits of $467,170 (59 cents) in the three months ended March 27 compared with $476,896 (51 cents) a year earlier, as revenues increased to $3.63 million from $3.30 million.

A company statement said despite a record March, the "severity of the winter caused increased maintenance and utility costs and loss of volume due to league cancellations and a mandated short week in Virginia," where 40 per cent of the firm's lanes are located.

For the nine-month period ended March 27, Bowl America earned $817,170 (87 cents) vs. $845,271 (90 cents) and revenues rose to $8.96 million from $8.12 million.

Fair Lanes, based in Baltimore, reported profits of $1.7 million (57 cents a share) in the quarter ended March 31 compared with $1.48 million (50 cents) a year ago. Revenues increased to $12.3 million from $11.4 million. Nine-month profits were $3 million ($1.01), up 19 per cent on an increase of 9 per cent in revenues to $32 million.