What's the most natural treatment for hyperparathyroidism?

Phosphate control: Parathyroid levels can be kept in check naturally by maintaining a low level of phosphate intake. Adequate vitamin d supplementation in the form of cholecalciferol is also helpful.

Depends on type: In the case of secondary hyperparathyroidism seen in the setting of significant renal insufficiency/chronic kidney disease the first step is to limit phosphorus intake in the diet. Dairy products and food high in protein can be sources of phosphorus. A dietician can review in details those foods that should be moderated.