Brittle Hair & Nails  Possible Deficiency: Biotin (Vitamin B7) You may also feel tired or have muscle cramps.

Cracks at the Corners of the Mouth Possible Deficiency: Iron, Zinc, or B Vitamins Especially B2, B3, and B12.

Bleeding Gums  Possible Deficiency: Vitamin C Also leads to weak immunity and slow healing.

Vision Problems at Night Possible Deficiency: Vitamin A Can also cause dry eyes and difficulty adjusting to dark.

Bone Pain or Weakness Possible Deficiency: Vitamin D Also affects mood and energy levels.