People who eat more dairy while dieting end up with higher levels of vitamin D in their blood than those who eat less dairy—even if they both started out low on vitamin D.
Scientific Claim
In overweight and obese adults on a 12-week energy-restricted diet, consuming 3–4 daily servings of dairy increases serum 25-hydroxyvitamin D levels by approximately 17% compared to ≤1 serving per day, despite both groups starting with insufficient vitamin D status.
Original Statement
“There was a significant increase (P = 0.02) in serum 25-hydroxyvitamin D in the AD group... approximately a 17% increase by the end of the 12-week intervention.”
Evidence Quality Assessment
Claim Status
appropriately stated
Study Design Support
Design supports claim
Appropriate Language Strength
definitive
Can make definitive causal claims
Assessment Explanation
The RCT design with controlled feeding and direct measurement of serum biomarkers supports a causal claim. The verb 'increases' is accurate and supported by the data.
Evidence from Studies
Supporting (1)
People who ate more dairy (3–4 servings a day) while dieting had a bigger increase in their vitamin D levels than those who ate less dairy, even though everyone started with low vitamin D.