DOVER — Supplement manufacturer Thorne Research announced Wednesday it is pulling out of the Panhandle.

The company said it has approved construction of a 270,000-square-foot manufacturing facility in Summerville, S.C., which is located about 26 miles northwest of Charleston.

Thorne CEO Thomas McKenna said in a statement that the planned relocation follows two years of extensive evaluation and consideration of sites nationwide. The analysis included input from third-party experts who were retained as consultants.

The new facility will provide for state-of-the-art research and development, production, laboratory, distribution and business operations.

“The new facility in South Carolina will materially increase production capacity and productivity, and provide for planned increases in output, staffing, new product development and clinical trials,” McKenna said in the statement.

The company was founded by Al and Kelly Czap in 1984 in Seattle and relocated to Bonner County in 1990 amid expansion into international markets. Thorne has since broadened its line of products to include supplements for companion animals, detoxification aids and supplements for musculoskeletal and oncology support. Thorne merged with Diversified Natural Products in 2010.

Thorne’s northern Idaho workforce consists of 270 employees, who were informed on Wednesday of the company’s plans. Following the Thanksgiving holiday, McKenna said the company will be implementing workforce retention and relocation programs.

“Both of these programs have been carefully planned to contain very generous provisions for the entire north Idaho workforce,” McKenna said.

Word of Thorne’s announcement spread quickly on Wednesday, with some in the community alarmed at the loss of such a significant employer in Bonner County and wondering whether political efforts in Idaho could be mounted to persuade the company to stay.

McKenna said South Carolina Gov. Nikki Haley, in addition to other state and Berkeley County officials, were integrally involved in Thorne’s relocation and expansion plan.

Berkeley County is home to manufacturers such as Audio-Technica, philanthropic software maker Blackbaud, green products manufacturer Viva Holdings and clothing maker Fruit of the Loom, according to the county’s department of economic development. In addition to inducements offered by the state, Berkeley County boasts the lowest local government mill rate in the state, special source revenue credits, fees in lieu of taxes and local grant assistance.

Ground excavation for the Summerville facility is underway and construction is slated to begin in earnest in January 2017. It is expected to be fully operational by 2018.

“At that point — by the end of the year in 2018 — Thorne Research plans to exit and close its three current facilities in north Idaho,” McKenna’s statement said.