The Prospect of a Leafy Kale Species to Address Micronutrient Deficiencies

African leafy vegetables are an affordable, traditional food, easy to grow and often advised to improve dietary diversity. However, nutrient content can differ based on species and plant maturity. This study determined the nutrient content (N = 8; mg/100 g fresh, raw leaves) of a species of Brassica, known colloquially as “Venda kale” (VK), harvested at 5, 7, and 9 weeks after planting in peat moss and coir fiber, as a potential source to address micronutrient deficiencies. A significant (p < 0.05) progressive decrease in most nutrients was observed across harvest times, except for an increase in Mn (p = 0.004) and P (p = 0.001). Conversely, in generally consumed Swiss chard (SC) (Beta vulgaris L.), an increase (p < 0.05) in Na, Mn, and P was observed across harvest times, while K, Zn, and Ca content fluctuated, and the highest nutrient density at week 7. No significant difference across harvest times was observed in Mg (p = 0.097) and Fe (p = 0.142) content. At week 5, Fe, Zn, and Ca content were significantly higher (p < 0.05) in VK and lower (p < 0.05) in Na, Mg, and Mn than in SC at 7 weeks. Compared with nutrient-dense baby spinach (Spinacia oleracea), using Food Data Central (USDA), VK at 5 weeks was significantly higher in Ca (p < 0.001), Mn content was not significantly different (p = 0.513), and all other minerals were significantly lower (p < 0.05). Two servings (60 g) of VK provide >14% of the dietary reference intakes (DRI; males and females) for Ca and Mn. VK could be advised as an alternative to SC in addressing specific micronutrient deficiencies, but the overall mineral content is lower than that of baby spinach.