Vitamin D is often called the sunshine vitamin, yet millions of people worldwide are deficient without realizing it. This silent deficiency can slowly weaken your bones, immune system, mood, and overall health. Here are 10 hidden signs of vitamin D deficiency you should never ignore. 1. Constant Fatigue & Low Energy Feeling tired even after enough sleep? Low vitamin D affects energy production at a cellular level. 2. Frequent Illness or Infections Vitamin D strengthens your immune system. Deficiency can make you catch colds, flu, or infections more often. 3. Bone Pain & Weak Bones Vitamin D helps absorb calcium.…