Vitamin D

Studies in people

• Benefit

  Thyroid health²

  People with Hashimoto's often have low vitamin D, and taking vitamin D supplements lowered their thyroid antibody levels.

• Benefit

  Immune system and autoimmunity³

  In animal and human studies, vitamin D improved immune function, especially in autoimmunity.

Study type not stated

• Benefit

  Body-wide health effects⁴

  Vitamin D helps the immune system, heart, hormones, and metabolism, and may play a role in depression, pain, and cancer.

• Concern

  Breastfed babies need supplements⁶

  Breast milk has little vitamin D, so breastfed babies may need extra vitamin D drops.

• Benefit

  Athletic performance⁷

  Vitamin D seems very important for general health and for athletic performance.

• Concern

  Overall health effects⁸

  Scientists have gathered strong evidence that not having enough vitamin D affects bones and may play a role in other diseases.

• Benefit

  Gut health⁹

  Vitamin D helps the gut absorb calcium and may also calm gut inflammation and support the gut lining.

How it’s made and used

• Getting enough from diet⁵

  Vitamin D comes from sunlight on skin, plus foods like fish, mushrooms, eggs and fortified milk.

The signal at the top counts the findings in people and in animal and lab studies. A concern in studies of people outranks animal and lab studies, and “No concerns” needs at least two findings in people. Findings whose study type is not stated are shown but not counted. This page is a reference, not medical advice. It describes what regulators and published research say. Talk to a doctor or dietitian about your own diet.