The U.S. nutritional supplements market is going to maintain its average growth rate of just more than 6% per year through 2018, hitting sales of $16.4 billion in that year, according to a report from Research and Markets, “Nutritional Supplements in the U.S., 6th Edition.”

Growth in the market slowed in 2013 and the first part of 2014 due to negative press coverage of supplement safety and effectiveness, and the increase in consumer use of functional foods and beverages, the report noted.

Omega-3/fish oil and calcium/bone supplements were hit hardest, with sales declining by double digits in 2013. On the other hand, digestive health and probiotic sales were stronger, posting an almost 25% increase in sales of such supplements in the multi-outlet channel in 2013.

Looking ahead, Research and Markets predicted sales of nutritional supplements will experience an increased growth rate between 2014 and 2018, with sales expanding due to an aging population, rising consumer involvement in personal health and a growing expectation of personalization for virtually all services and products.