1. The calcium content in kelp is very high, but if eaten directly, the human body cannot absorb it well.

2. Vinegar is rich in amino acids, lactic acid, acetic acid and other "acids", which can dissolve calcium, iron and other minerals contained in kelp, thereby improving the body's absorption and utilization rate.

3. Kelp is a typical alkaline food. Regular consumption can help prevent the loss of calcium in the body.

4. Kelp soaked in vinegar has the effects of nourishing hair, lowering fat, lowering blood pressure, and replenishing calcium. After soaking for more than a month, the nutrition reaches its optimal state.