Vitamin D
Vitamin D is a fat soluble vitamin. It can be produced by the body in the presence of sunlight.
Vitamin D RDA (Recommended Dietary Allowance):
- Adults (19-70 years): 600 IU/day (15 mcg/day)
- Adults (71+ years): 800 IU/day (20 mcg/day)
- Pregnant and breastfeeding women: 600 IU/day (15 mcg/day)
ODA (Optimal Daily Allowance):
- 1,000-4,000 IU/day (varies depending on individual needs, sun exposure, and health goals)
Found in:
- Fatty fish (salmon, mackerel, tuna, sardines)
- Cod liver oil
- Egg yolks
- Fortified foods (milk, orange juice, cereals)
- Mushrooms exposed to sunlight (e.g., UV-treated varieties)
- Sunlight exposure (skin synthesizes vitamin D when exposed to UVB rays)
Helps with:
- Promoting calcium absorption and bone health
- Supporting immune system function
- Regulating mood and reducing risk of depression
- Enhancing muscle function
- Reducing risk of chronic diseases (e.g., osteoporosis, cardiovascular disease)
- Potentially lowering the risk of certain cancers
Insufficient doses:
- Symptoms of deficiency:
- Fatigue and weakness
- Bone pain and muscle weakness
- Increased risk of fractures
- Depression and mood changes
- Weakened immune response
- Severe deficiency can lead to rickets in children and osteomalacia in adults (softening of bones).
Excessive doses:
- Upper limit: 4,000 IU/day for most adults
- Possible side effects of high doses:
- Nausea and vomiting
- Poor appetite and weight loss
- Hypercalcemia (elevated calcium levels), which can lead to kidney damage
- Calcification of soft tissues (e.g., blood vessels, kidneys)
Interactions:
- Synergy:
- Works with calcium and magnesium to support bone health.
- Enhances phosphorus absorption (important for bone and cellular function).
- Synergistic effects with vitamin K2 for directing calcium to bones and away from soft tissues.
- Antagonistic interactions: