A damaged disc in the lower lumbar region may cause sacrum pain as it compresses the spinal nerves. A bulging or herniated disc is often the result of too much sitting with associated poor posture. Improving posture and relieving pressure on the disc will facilitate healing. Contracted psoas muscle.
Bananas are very rich in potassium, magnesium and calcium... and pink grapefruit. Milk is high but so is it's fat content. Enriched sources are traditionally cereals, as without the added vitamins they would be almost nutritionally worthless.
Magnesium activates enzymes, contributes to energy production, and helps regulate levels of calcium, copper, zinc, potassium, vitamin D, and other important nutrients in the body. You can get magnesium from many foods.