25‐hydroxy D and Its Relationship to Potential Sources

Abstract

Vitamin D status is associated with bone health and with cardiovascular health, diabetes mellitus and cancer. Since vitamin D status is affected by food and supplement intake and by sun exposure, the ability to accurately predict vitamin D status assessed from these sources is important. The objective of this study is to evaluate the use of 3‐day diet records (3DR) including dietary supplements and a food frequency questionnaire (FFQ) not including dietary supplements to predict serum 25‐hydroxyvitamin D concentrations [25(OH)D] in 40 male and female subjects (30 to 69 yrs). Time spent in sunlight was self‐reported along with a Fitzpatrick Skin Type Questionnaire. Vitamin D intake from the 3DR was positively correlated with 25(OH)D with a curvilinear relationship and may be used to predict 25(OH)D (rs=0.60, P <0.001). FFQ was not correlated with 25(OH)D (rs=0.15, P=0.38) but the FFQ with supplements was positively correlated (rs=0.42, P=0.013). Unprotected sun exposure or skin type did not aid the ability to predict 25(OH)D levels possibly due to winter month data collection with minimum unprotected sun exposure. Intake of vitamin D from supplements must be considered when estimating vitamin D status.