Why do I need a vitamin D test?

Your provider may order a vitamin D test if you have signs or symptoms of a bone condition that may be related to a vitamin D deficiency (very low levels of vitamin D), such as:

• Bone pain
• Muscle weakness or aches
• Soft bones
• Deformed bones
• Weak bones and fractures (broken bones)
• Low bone density (osteoporosis or osteopenia)

A vitamin D insufficiency (mildly low levels of vitamin D) usually doesn’t cause symptoms. So, your provider may order a test if you have a high risk for developing a deficiency because you:

• Are older than 65. As you age, your skin is less able to make vitamin D from sunlight.
• Rarely expose your skin to sunshine because you stay indoors, cover up outside, use sunscreen, or live where there is little sunlight
• Have dark skin, which makes less vitamin D from sunlight
• Have had weight loss surgery
• Have obesity
• Have a condition that makes it difficult to absorb nutrients in food, such as Crohn’s disease, ulcerative colitis, and celiac disease
• Have kidney or liver disease that affects your ability to change vitamin D into a form your body can use
• Take certain medicines that affect your vitamin D levels

A lack of vitamin D can cause serious problems for babies and children. A provider may order a screening test for:

• Babies that are mainly fed breastmilk. Breastmilk is low in vitamin D (All babies need vitamin D supplements shortly after birth, unless they are fed only formula, which contains vitamin D.)
• Children with darker skin who live in areas with little sunlight
• Children with diets low in vitamin D

If you are taking vitamin D supplements to increase your vitamin D level, your provider may order a test to see if your vitamin D levels are improving.