Dietary Supplement. Compare & save. Vitamins. Calcium promotes healthy, strong bones and is helpful in muscle contractions and nerve impulses. The addition of D3 assists with the absorption of calcium while also supporting a healthy immune system. 100% quality guarantee. naturestruthproducts.com. Promotes bone health. May reduce the risk of osteoporosis (Adequate calcium and vitamin D as part of a healthful diet, along with physical activity, may reduce the risk of osteoporosis in later life). (These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.).