The purpose of these systematic review and meta-analysis was to assess the effectiveness of dairy components on nutritional status and physical fitness in older adults, as evidence for efficacy of the supplementation of these components is inconclusive. Scopus and MEDLINE were searched. Main inclusion criteria for articles were as follows: double-blind, randomized, placebo-controlled trials including participants aged ≥55 years who received dairy components or a placebo. Outcome measures were nutrient status (body weight and body mass index) and physical fitness (body composition, muscle strength, and physical performance). Thirty-six trials with 4947participants were included. Most trials investigated protein and vitamin D supplementation and showed no effect on the outcomes. Meta-analysis on the effect of protein on body weight showed a significant increase in mean difference of 1.13 kg (95% confidence interval, 0.59-1.67). This effect increased by selecting trials with study a duration of 6 months in which less nourished and physically fit participants were included. Trials where the participants were (pre-)frail, inactive older adults or when supplementing ≥20 g of protein per day tended to increase lean body mass. Only small significant effects of vitamin D supplementation on Timed Up and Go (mean difference -0.75 seconds; 95% confidence interval -1.44 to -0.07) were determined. This effect increased when vitamin D doses ranged between 400 and 1000 IU. Additional large randomized controlled trials of ≥6 months are needed regarding the effect of dairy components containing an adequate amount of vitamin D (400-1000 IU) and/or protein (≥20 g) on nutritional status and physical fitness in malnourished or frail older adults.

The aging process is often accompanied by increase in body weight. Older adults with overweight or obesity might have an overconsumption in energy that is accompanied by inadequate intake of protein, vitamin D, and calcium. It is unclear if intake of protein and vitamin D and calcium is sufficient in older adults with overweight/obesity, and whether it differs from older adults with normal weight, since a recent overview of the literature review is lacking. Therefore, we systematically analyzed the current evidence on differences in nutrient intake/status of protein, vitamin D and calcium between older adults with different body mass index (BMI) categories. Randomized controlled trials and prospective cohort studies were identified from PubMed and EMBASE. Studies reporting nutrient intake/status in older adults aged ≥50 years with overweight/obesity and studies comparing between overweight/obesity and normal weight were included. Nutrient intake/status baseline values were reviewed and when possible calculated for one BMI category (single-group meta-analysis), or compared between BMI categories (meta-analysis). Nutrient intake/status was compared with international recommendations. Mean protein (N = 8) and calcium intake (N = 5) was 0.98 gram/kilogram body weight/day (g/kg/d) [95% Confidence Interval (CI) 0.89–1.08] and 965 mg [95% CI: 704–1225] in overweight/obese. Vitamin D intake was insufficient in all BMI categories (N = 5). The pooled mean for vitamin D intake was 6 ug [95% CI 4–9]. For 25(OH)D, the pooled mean was 54 nmol/L [95% CI 45–62], 52 nmol/L [95% CI 46–58], and 48 nmol/l [95% CI 33–62] in normal (N = 7), combined overweight and obese (N = 12), and obese older adults (N = 4), respectively. In conclusion, older adults with overweight and obesity have a borderline sufficient protein and sufficient calcium intake, but insufficient vitamin D intake. The 25(OH)D concentration is deficient for the obese older adults.

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