Association between dietary diversity score and nutrient adequacy among older adults in Blouberg Municipality, Limpopo Province, South Africa

Dietary diversity is widely used as an indicator of diet quality and micronutrient adequacy, yet evidence among rural South African older adults remains limited. This study evaluated the Dietary Diversity Score (DDS) as a proxy measure of nutrient adequacy among older adults in Blouberg Municipality, Limpopo Province. A community-based cross-sectional study was conducted among 429 older adults aged ≥ 60 years. Participants were recruited using snowball sampling. Dietary intake was assessed using a 24-hour dietary recall based on the 12 Food and Agriculture Organization food groups. Nutrient Adequacy Ratios (NARs) and the Mean Adequacy Ratio (MAR) were calculated using FoodFinder III™. MAR values ≥ 0.75 were considered indicative of adequate nutrient intake. Associations were assessed using Chi-square tests, independent t-tests, and multivariable logistic regression, with statistical significance set at p < 0.05. Most participants had moderate (62.7%) or high (33.1%) DDS, and 56% achieved overall nutrient adequacy, defined as mean adequacy ratio (MAR) ≥ 0.75. Higher DDS was associated with significantly better adequacy of protein, carbohydrates, calcium, iron, vitamins A, C, E, niacin, and cobalamin ( p < 0.05). Selenium adequacy was also higher among participants with higher DDS, although the difference was not statistically significant. After adjusting for potential confounders, dietary diversity remained the only independent predictor of nutrient adequacy, with participants in the high DDS group more than four times as likely to achieve adequate nutrient intake (AOR = 4.21; 95% CI: 1.98–8.95). Higher dietary diversity was associated with better nutrient adequacy among rural older adults. These findings suggest that promoting dietary diversity may contribute to improved nutrient intake in this population. However, further research is needed to determine the potential usefulness of the Dietary Diversity Score (DDS) as a practical approach for identifying older adults at risk of inadequate nutrient intake in resource-limited rural settings.