Guide

Low vitamin D in adults usually comes from little sun, low dietary intake, malabsorption, higher needs, some conditions, or certain drugs.

Low vitamin D in men often stems from limited sun, low dietary intake, higher body fat, gut or liver disease, kidney problems, and certain medicines.

Low vitamin D in women often comes from limited sun, low vitamin D foods, higher body fat, hormone changes, and health or medicine effects.

Common causes of decreased vitamin D levels include low sun exposure, limited dietary intake, darker skin, obesity, certain medicines, and gut or kidney

Low vitamin D levels usually stem from limited sun exposure, low dietary intake, higher skin pigmentation, ageing, obesity, or medical conditions.

Low muscle mass usually comes from aging, inactivity, low protein intake, chronic illness, hormone shifts, or nerve and joint disease.

High calcium with low vitamin D usually points to hormone, cancer, medication, or inflammatory problems that need careful medical evaluation.

Low ferritin and vitamin D often drop together due to low intake, blood loss, poor absorption, limited sun time, or chronic illness.

Chronic vitamin D deficiency comes from low sun exposure, poor dietary vitamin D, certain medical disorders, and medicines that affect vitamin D.

Elevated cortisol often comes from chronic stress, health conditions, medicines, sleep loss, and daily habits that strain the stress system.