Overall, mean serum 25(OH)D was lower in 2000-2004 than 1988-1994. Assay changes unrelated to changes in vitamin D status accounted for much of the difference in most population groups. In an adult subgroup, combined changes in BMI, milk intake, and sun protection appeared to contribute to a real decline in vitamin D status.

Part of the problem is that industrialised foods such as refined flours and omega6 vegetable oils may be contributing to our increasing inability to metabolize Vitamin D from our diet or store it from sunshine. Our bodies are increasingly showing signs of inflammation while our intake and reserves of natural anti inflammatories like vitamin D3, omega 3, magnesium are declining.