A fast-growing manufacturer of vitamins and generic prescription drugs is nearly quadrupling, to $12.2 million, its spending on improvements to a factory, warehouse and office in Hauppauge, officials said.

A&Z Pharmaceutical Inc. has increased its planned investment in 350 Wireless Blvd. from $3.2 million, a figure set in February 2016, because of strong demand for its products, according to the Suffolk County Industrial Development Agency.

The company also will add 15 jobs to its payroll of 115 in the next two years. It had 62 employees three years ago.

A&Z is a major exporter of vitamins to China, shipping millions of tablets of a vitamin D and calcium supplement each year.

The company is among about 25 makers of vitamins, dietary supplements and nutritional ingredients that call Long Island home and together have created hundreds of jobs in recent years.

“We anticipate further growth,” A&Z attorney Peter L. Curry said last week at a meeting of the IDA’s board of directors.

advertisement | advertise on newsday

He said A&Z will install additional production lines in 23,400 square feet of space at the Wireless Boulevard building that had been earmarked for warehousing.

As a result, a planned 26,500-square-foot addition to the 118,000-square-foot building will become a warehouse.

A&Z purchased the Wireless Boulevard facility in 2014, adding to its rented space in two other buildings, also in Hauppauge. The purchase price was about $12.6 million, and the company spent about $16 million on improvements and equipment.

A&Z’s increased investment in the Wireless Boulevard building makes it eligible for a larger sales tax exemption from the IDA on the purchase of construction materials, fixtures and other supplies, IDA executive director Anthony J. Catapano said Monday.

The IDA has granted $1.1 million in tax breaks for the building expansion and other improvements proposed in 2016 and last week. This is on top of $1.7 million awarded in 2014 when A&Z purchased the building and did a first round of renovations.

Catapano said A&Z “has met the job commitment it gave to us in 2014 and is very close to meeting the commitment made last year. . . . They are ahead of schedule.”

Stephen Latuso, the company’s CFO, said workers are paid between $20,000 and $50,000 per year, on average. They also participate in an annual profit-sharing program equal to 3 percent of their salary at year end.

Latuso said the Wireless Boulevard building will include employee amenities such as a gym and cafeteria.

In addition to $2.8 million in IDA tax breaks, A&Z has won an allocation of cheap electricity and $1.5 million in tax credits from New York State.

The company opened in the mid-1990s as the U.S. subsidiary of a Chinese government-backed pharmaceutical giant led by the father of A&Z CEO Emma Li Xu. More recently, she has assumed sole ownership of the company, which takes its name from America and Zhongguo, the Chinese word for China.