Vitamin D Deficiency: Symptoms, Normal Range and When to Test

Studies repeatedly find that a large majority of Indians have insufficient vitamin D — even in sunny cities. Because symptoms are vague, deficiency often goes unnoticed for years while it quietly affects bones, muscles and immunity.

Common symptoms of low vitamin D

• Persistent tiredness and low energy
• Bone pain, lower-back pain and muscle aches
• Frequent infections
• Slow wound healing, hair fall and low mood

Vitamin D (25-OH) ranges

• Deficient: below 20 ng/mL
• Insufficient: 20–29 ng/mL
• Sufficient: 30–100 ng/mL
• Potentially toxic: above 100 ng/mL — usually from over-supplementation

Who should get tested?

Anyone with the symptoms above, people who work indoors, women after menopause, people with diabetes or thyroid disorders, and anyone starting long-term supplements. The test measures 25-hydroxy vitamin D — the storage form and the best marker of your status. No fasting is required.

If your level is low, doctors typically prescribe a weekly high-dose supplement for 8–12 weeks and then retest. Don't self-prescribe mega-doses — toxicity is real, and your doctor will set the right course.