Vitamin D

What is Vitamin D? A fat-soluble vitamin that functions like a hormone. It is unique because your body can make it through sun exposure, but it can also be consumed through food and supplements.

Two forms:

• Vitamin D3 – cholecalciferol – found in animal-based foods and made in the skin
• Vitamin D2 – ergocalciferol – found in some plant-based sources and fortified foods

Too Little Vitamin D:

• Rickets – in children – bone deformity, seizures, dental abnormalities, developmental delay
• Osteomalacia or osteoporosis – weak bones and fractures in adults
• Fatigue, muscle pain – often subtle 
• Frequent illness 

Groups at Risk for Deficiency:

• Those with limited sun exposure (northern latitudes, indoor lifestyle)
• Breastfed infants
• Darker skin tones (need more sun to make vitamin D)
• Older adults
• Obesity or fat malabsorption (celiac, Chron’s, cystic fibrosis, ulcerative colitis)

Too Much Vitamin D (from supplementation):

• Nausea, vomiting, weakness
• Kidney stones, kidney failure
• Calcification of soft tissues
• Cardiac arrythmia, death
• No risk of toxicity from sun exposure or food alone

Just Right (adults):

Recommended 600-800 IU/day

Medication Interactions

(consult your doctor)

• Orlistat (weight loss)
• Statins (cholesterol)
• Steroids
• Thiazide diuretics

Food Sources

Animal

• Fatty Fish – best natural source of D3 – trout, salmon, tuna
• Cod Liver Oil – extremely high in D, but also A (watch dosing)
• Egg Yolks 
• Butter and Liver 

Fortified

• Dairy – cow’s milk, oat, soy and almond
• Cereals 

Plant based

• UV-Exposed Mushrooms – only significant source of D2

Cooking tip:

Vitamin D is fat-soluble, so it’s best absorbed when eaten with a source of fat (oil, avocado, nuts).

Reference: Vitamin D – Health Professional Fact Sheet