I have had severe hip pain which has spread to my knees; my neck is stiff also. My worst symptoms are fatigue, restless legs, pain in the arches of my feet. My Vit. D level is 14 but my iron , b12 and ferritin are also low. My dr. started me on 50,000 of Vit. d and Niferex Forte and get re-checked in 1 month. I am hoping my symptoms go away by then.