Ergocalciferol

Studies in people

• No harm found

  Long-term supplement side effects²

  Taking ergocalciferol for months did not raise stomach or skin complaints or make people quit studies.

• Benefit

  Bone strength and blood calcium³

  Ergocalciferol (vitamin D2) raised calcium and lowered parathyroid hormone in people, which may help keep bones strong.

• Open question

  Vitamin D levels in the body⁵

  Ergocalciferol may raise vitamin D levels less than vitamin D3, but scientists do not yet know for sure.

• Benefit

  Vitamin D levels in children⁸

  Young Chinese children with ergocalciferol in their blood were less likely to be low in vitamin D.

• No harm found

  Vitamin D levels in women⁹

  In women, vitamin D2 from UV-treated yeast in bread did not raise vitamin D levels in the blood.

• Benefit

  Vitamin D levels in metabolic syndrome¹⁰

  In people with metabolic syndrome, weekly ergocalciferol raised vitamin D levels, with more reaching normal at the higher amount.

• Concern

  Muscle soreness after exercise¹¹

  In NASCAR pit crew athletes, six weeks of ergocalciferol led to more signs of muscle damage after hard exercise.

Study type not stated

• Open question

  Vitamin D in the body¹²

  Scientists are still working out how well ergocalciferol from supplements stands in for the vitamin D your body makes.

How it’s made and used

• Vitamin D levels in the blood⁴

  Ergocalciferol raised vitamin D levels less than another form of vitamin D, especially when taken in single large doses.

• Vitamin D in the diet⁶

  Most Irish adults had signs of ergocalciferol in their blood, suggesting they eat it without knowing.

• Vitamin D forms compared⁷

  Ergocalciferol and vitamin D3 are both vitamin D, but studies show vitamin D3 raises blood levels more.

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 one finding in people. When most findings in people point one way, the page leans that way (“Mostly”), and every finding is still shown. 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.