Biochemical markers of nutritional status, such as adipose tissue fatty acid composition and circulating levels of micronutrients, may reflect dietary habits, but may also be related to inflammatory activity. We examined the relationship between common rheumatic complaints such as osteo-arthrosis, arthralgia, tendinitis, low-back pain, and neck pain, and the composition of adipose tissue fatty acids, serum concentrations of retinol, ascorbic acid, alpha-tocopherol and selenium in 502, out of 900 randomly selected individuals 50-70 years old. Compared with control subjects the rheumatic group as a whole (p less than 0.01) as well as subgroups like those with arthralgia (p less than 0.01), subacromial shoulder pain (p less than 0.03), and low-back pain (p less than 0.05), had decreased proportions of adipose tissue arachidonic acid. The abnormalities correlated with the duration of the symptom-free period preceding adipose tissue sampling and could not be explained by the evaluation of possible confounding factors. Regarding other fatty acids and micronutrients there were no differences between symptomatic subjects and controls. One explanation for the low proportion of adipose tissue arachidonic acid may be increased eicosanoid production.