Natural Grocers by Vitamin Cottage's (NYSE: NGVC) comparable store sales came in below analyst expectations, yet the company outlook for fiscal 2016 remains firm, according to earnings released Thursday.

The Colorado-based health food store chain’s leadership cited increased competition and a softening economy, particularly in oil-producing states, for financial results and noted that they expect the second quarter to perform below the outlook range.

First-quarter highlights for Natural Grocers' fiscal year 2016 included:

Promotion plans boost Co-President Kemper Isely’s positivity for the year. Natural Grocers began experimenting with a loyalty program and personalized offers in December that have resulted in significant basket size growth among users. The program will roll out more widely.

The health food retailer also has adopted a companywide promo calendar with special events planned each month. A spa day can result in 20 percent sales lift, Isely said.

Meanwhile, the company remains committed to nutrient education, which Isely noted as key to supplement sales. Even with competition and media scrutiny of the category growing, comparable store sales for supplements remained flat. Isely said he has not heard customer concern about recent media reports the supplement industry has considered negative and reported that education efforts in fact grow sales. Nutrients that are the focus of an education promotion see 200 percent growth in the quarter and as much as 100 percent the following quarter, he said.

The reiterated 2016 fiscal outlook is: