Calcium is an essential mineral with critical roles in skeletal integrity, neuromuscular function, and metabolic regulation. This study evaluated the dietary calcium intake of a Cuban adult population using the Total Diet Study (TDS) methodology. A 24-hour dietary recall was conducted in a representative sample of 450 individuals, and 107 food items were analyzed via flame atomic absorption spectroscopy after dry ashing. Milk and dairy products were identified as the primary source of calcium, contributing 47.8% (328.6 mg/day) of the total daily intake, followed by non-alcoholic beverages, bread and flour products, and fish. The average daily calcium intake was 687 mg/day, notably below the EFSA recommended intake (860–1000 mg/day). The prevalence of adequate calcium intake was 69%, which is lower than in other countries such as Spain, Italy, or Iran. Despite being under the recommended range, the intake did not exceed the tolerable upper limit (2500 mg/day), suggesting no immediate risk of toxicity. No significant differences in calcium intake were observed between sexes or age groups. However, the low calcium-to-phosphorus molar ratio (0.44:1) observed may contribute to adverse health outcomes such as bone demineralization or secondary hyperparathyroidism. These findings underline the need for national nutritional policies that promote the consumption of calcium-rich food to prevent long-term health issues, including osteoporosis and colorectal cancer.