What kind of supplementary foods should be added in three months?

Patient's question:

My daughter is already three and a half months old. Whatshould I add?

Doctor's answer:

Dietary Principles
In the first year after birth, infants have rapid growth and development and high activity levels, requiring more nutrients per kilogram of body weight compared to adults. From 1 to 6 months of age, infants need 110 to 120 kilocalories per kilogram of body weight per day, while infants aged 7 to 12 months need 100 to 110 kilocalories. For children under one year old, the protein requirement is 3 to 4 grams per kilogram of body weight per day, and the calcium requirement is approximately 600 milligrams. Only 20 to 30% of calcium in the diet can be absorbed because the intestinal contents are alkaline, and oxalates and phosphates in food can hinder calcium absorption by forming insoluble calcium compounds. Vitamin D, sunlight, and acidic intestinal conditions, however, promote calcium absorption. The calcium-to-phosphorus ratio in breast milk is 2:1 (compared to 4:3 in cow's milk), which is more suitable, so calcium absorption from breast milk is higher than from cow's milk.
Water is the main component of cells and plays a role in transporting nutrients and excreting metabolic waste in the body. The younger the age, the faster the metabolism, and the greater the water requirement. A diet high in salt and protein increases water needs, while sugar retains water. If an infant overeats starchy foods, their weight may temporarily increase, but insufficient water supply can lead to symptoms such as thirst, reduced urine output, and the accumulation of acidic metabolic substances. Excessive water intake, on the other hand, can cause pulmonary edema and increased blood circulation. Thus, water is as vital to an infant's life as air is.
A normal infant at 3 days old requires 250 to 300 milliliters of water (including milk) per day. From 3 to 10 days of age, daily water intake should be 400 to 500 milliliters. From 10 days to 3 months, the daily water requirement is 750 to 850 milliliters. From 4 to 6 months,