Is Vitamin D2 Treatment-associated Decrease in 25(OH)D3 Level a Reciprocal Phenomena?

Is Vitamin D2 Treatment-associated Decrease in 25(OH)D3 Level a Reciprocal Phenomena? A Randomized Controlled Trial

Several studies have demonstrated that D2 treatment is associated with a decrease in 25(OH)D3 level and therefore have proposed that D3 would be preferable in term of raising total 25(OH)D level. The investigators postulate that the D2 treatment-associated decrease in 25(OH)D3 level may be related to an increase in total 25(OH)D level rather than being specific to D2 treatment, and thus there would be a D3 treatment-associated decrease in 25(OH)D2 level.

The investigators plan to conduct a double-blind placebo-controlled trial to examine the effect of D3 treatment on 25(OH)D2 level and the effect of D2 treatment on 25(OH)D3 leve

Inclusion criteria:

• non-pregnant adults (age ≥18 years)
• healthy
• total 25(OH)D level between 20 to 65 nmol/L.
• living in Riyadh area

Exclusion criteria:

• consumption of more than one serving of milk daily
• taking vitamin D supplements
• habitual weekly sun exposure of 10 hours or more
• history of granulomatous, liver, or kidney disease
• taking anticonvulsants, barbiturates, or steroids