Conjugated linoleic acids (CLA) are conjugated isomers of linoleic acid, which may promote health with regard to cancer, heart disease, diabetes, bone formation, growth modulation and immunity. The c9,t11 isomer of CLA, rumenic acid (RA), is the major isomer present in the diet. However, dietary intakes of CLA and RA by humans have not been examined rigorously, nor has the relationship between dietary CLA or RA and health (e.g., body composition). Three-day dietary records (DR) were collected from adult men (n = 46) and women (n = 47) and analyzed using a nutrient database modified to contain total CLA and RA. Simultaneously, 3-d food duplicates (FD) were collected to determine analytically individual fatty acid intakes, including those of total CLA and RA. Chronic total CLA and RA intakes were estimated using a semiquantitative food-frequency questionnaire (FFQ). Body composition was estimated using body mass index and percentage of body fat. Total CLA intake was estimated from FD to be 212 +/- 14 and 151 +/- 14 mg/d (mean +/- SEM) for men and women, respectively; RA intake was estimated to be 193 +/- 13 and 140 +/- 14 mg/d for men and women, respectively. In general, CLA and RA intakes estimated by DR and FFQ were significantly lower than those estimated by FD. Body composition was not significantly related to dietary total CLA or RA intake. In conclusion, results suggest that DR and FFQ methodologies are not reliable estimators of individual total CLA and RA intakes and may underestimate total CLA and RA intakes of groups. Intake of total CLA and RA was found to be significantly lower than that suggested previously by others.

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This paper describes key aspects of a scientific workshop focused on current knowledge, unresolved questions and future research needs in the area of human milk lipids and their physiological effects in infants.

Vitamin D plays an important role in human health. Current recommendations for vitamin D intake and endogenous supply through sun exposure are not met in German pre-school children, and suboptimal serum 25-hydroxyvitamin D concentrations, especially during the winter months, are common. Consequently, vitamin D supplementation or fortification have gained increased acceptance. The KiMi trial (Kindermilch=growing up milk) was a prospective, randomized, and double-blind study in which young children (2-6 years of age, n=92) were assigned to receive either vitamin D-fortified growing up milk (2.85 μg/100 ml) or semi skimmed cow's milk without added vitamin D. Daily consumption of fortified growing up milk contributed to the prevention of an otherwise frequently observed decrease in serum 25-hydroxyvitamin D concentration during winter (before winter: median 21.5 ng/mL (10.1-43.0 ng/mL) intervention vs. median 18.4 ng/mL (11.0-44.9 ng/mL) control; after winter: median 24.8 ng/mL (7.0-48.2 ng/mL) intervention vs. median 13.6 ng/mL (7.0-36.8 ng/mL) control) and proved to be safe during summer (median 27.6 ng/mL (18.8-40.5 ng/mL) intervention vs. median 27.4 ng/mL (17.8-38.7 ng/mL) control). Due to the high prevalence of vitamin D deficiency, fortification of growing up milk with vitamin D at a level used in this study could be an effective measure to improve vitamin D status.

Isomers of conjugated linoleic acid (CLA) decreased milk fat, altered immunity, and reduced the risk for cardiovascular disease (CVD) in some animals. The major form of CLA in the human diet is c9,t11-18:2 (rumenic acid; RA). We studied the effects of high RA consumption on plasma and milk RA concentration, milk composition, immunity, and CVD risk factors in lactating women (n = 36) assigned to 1 of 3 treatments: control, low CLA cheese (LCLA; 160 mg RA/d), or high CLA cheese (HCLA; 346 mg RA/d). The increase in plasma RA concentration between baseline and 8 wk in women consuming HCLA cheese was significantly greater than that of controls. At study completion (8 wk), milk RA concentration among women consuming HCLA cheese was greater (P < 0.05) than that of controls (0.37 vs. 0.26% of fatty acids). Treatment did not affect milk fat, protein, or lactose concentrations, immune indices (e.g., plasma T-helper cells and interleukin-2), or measured risk factors for CVD (e.g., plasma triacylglyceride and cholesterol). In summary, consumption of a RA-enriched cheese modestly increased plasma and milk RA concentrations without affecting total milk fat, plasma and milk indices of immunity, or selected risk factors for CVD.