Vitamin D

Definition

Vitamin D is a fat-soluble vitamin essential for maintaining healthy bones and supporting the immune system.

Scientific / Technical Definition

Vitamin D refers to a group of fat-soluble secosteroids responsible for increasing intestinal absorption of calcium, magnesium, and phosphate, and multiple other biological effects. The two main forms are vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol).

Benefits

• Supports healthy bone development and maintenance
• Boosts immune system function
• Reduces inflammation
• Contributes to normal muscle function
• May reduce the risk of chronic diseases such as multiple sclerosis and heart disease

Examples

• Fatty fish (e.g., salmon, mackerel, sardines)
• Fish liver oils
• Fortified dairy and plant milk products
• Egg yolks
• Mushrooms exposed to sunlight

Additional Information

• Importance: This nutrient is important for bone health and immune system support.
• Side effects: Excessive vitamin D intake can lead to toxicity, causing nausea, weakness, and kidney damage.

Related Terms

• Calcium
• Bone Health
• Immune System
• Osteoporosis

References

• Vitamin D: Fact Sheet for Health Professionals
• Vitamin D and Health