lightening the load that you carry on yer back, as well as making sure you have supportive straps, and hip straps on the bag, to balance the weight distribution of yer pack, is a good way to maintain healthy bones. Stretching daily is good too, because gravity+weight=joint and muscle compaction. Building muscle helps to build strong, healthy bones, because the muscle pulls on the bones, encouraging it to toughen up. Kind of like the way love does to a heart i supose.
bone marrow soup stock or broth will provide your body with essential bone building materials. Eating lots of dark and leafies, and cruciferous veggies provides a lot of calcium. Glucosamine with chondroitin is a good bone supplement to take. Eating foods that contain silica (or taking a supplement), like cucumber, helps to lubricate your joints, tendons, ligaments, and cartilage. Yoghurt is really good for your bones too, especially if you have high lactose intolerance. If you eat canned fish, eat the kind with bones in.
Minerals are hard to come by b/c our food is grown in minerally depleted soils.
Sea weed and vegetables contain a lot of minerals, and taste delicious.
Keeping a strong core, legs, and balance will maintain a healthy back. Paying attenting to how you are twisting/turning/lifting/reaching will help you avoid straining your back. If you don't know what it means to 'lift with your legs' then get someone to show you. Lifting something heavy, very carefully shouldn't hurt your back, unless you already have problems, or do it too much.
