Scientists from Deakin University have found that eating one egg per day during winter may help maintain healthy vitamin D levels.
Vitamin D is a fat-soluble vitamin that helps the body absorb and retain calcium and phosphorus, both of which are essential for building and maintaining strong bones.
Previous studies have also shown that vitamin D may help reduce cancer cell growth, support immune function, and decrease inflammation.
Vitamin D supplements are available in two forms: vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol).
Few foods naturally contain vitamin D, although some foods are fortified with it. For many people, supplements are a common way to meet daily needs.
Vitamin D can also be produced in the skin when exposed to the sun’s ultraviolet-B (UVB) rays. However, vitamin D deficiency is a common health concern during winter, when sunlight exposure is reduced.
Eggs are one of the few natural dietary sources of vitamin D, containing both cholecalciferol (vitamin D3) and 25-hydroxyvitamin D3, the latter of which may be up to five times more effective at raising vitamin D levels in the body.
However, the optimal number of eggs needed to maintain healthy vitamin D levels during winter has remained unclear.
In the current study, researchers examined how consuming 2, 7, or 12 commercially available eggs per week affected vitamin D levels during the autumn and winter months in young adults.
In the 12-week trial, 51 adults aged 25 to 40 were assigned to eat either 2 eggs per week, 7 eggs per week, or 12 eggs per week. Forty-two participants (82%) completed the study.
The researchers measured changes in vitamin D levels over time. They found that vitamin D levels remained stable in both the 7-egg and 12-egg groups but declined significantly in the group consuming only 2 eggs per week.
This resulted in a clear difference between groups after 12 weeks. Participants across all groups reported positive experiences with egg consumption.
Based on the findings, the researchers concluded that eating seven commercially available eggs per week for 12 weeks may help prevent the typical winter decline in vitamin D levels.
Future studies are needed to determine whether similar benefits occur in older adults.
The research was published in The Journal of Nutrition and conducted by Professor Robin Daly and colleagues.
