Back to all nutrients
Vitamins
Vitamin D
The sunshine vitamin essential for bone health, immune function, and mood regulation
Quick Facts
Daily Needs
600-800 IU (15-20 mcg) per day for adults, with higher needs for older adults
Importance
Vitamin D is crucial for calcium absorption, bone mineralization, immune function, and may help prevent various chronic diseases.
Key Functions
- •Calcium absorption for bone health
- •Immune system regulation
- •Cell growth and division
- •Neuromuscular function
- •Inflammation reduction
- •Glucose metabolism support
Deficiency Signs
- •Bone pain and tenderness
- •Muscle weakness and aches
- •Fatigue and tiredness
- •Mood changes and depression
- •Impaired wound healing
- •Increased susceptibility to infections
- •Hair loss
- •Bone loss and increased fracture risk
Excess Signs
- •Hypercalcemia (excess calcium in blood)
- •Nausea and vomiting
- •Weakness
- •Frequent urination
- •Kidney stones
- •Kidney damage
- •Calcification of soft tissues
Best Food Sources
- •Fatty fish (salmon, mackerel, sardines)
- •Cod liver oil
- •UV-exposed mushrooms
- •Fortified foods (milk, orange juice, cereals)
- •Egg yolks
- •Beef liver
- •Cheese
Absorption Facts
- •Fat-soluble - best absorbed with dietary fat
- •Sunlight (UVB) exposure triggers vitamin D synthesis in skin
- •Darker skin requires more sun exposure to produce same amount
- •Absorption decreases with age
- •Obesity reduces bioavailability
Special Considerations
- •People in northern latitudes often need supplements in winter
- •Those with limited sun exposure are at higher risk of deficiency
- •Sunscreen blocks vitamin D synthesis
- •Older adults have decreased synthesis capacity
- •Those with fat malabsorption disorders may need specialized forms
About Vitamin D
Loading content...