The primary aim of the current study was to investigate whether the consumption of vitamin D3 enriched, reduced-fat yellow cheese can counterbalance the expected decrease in serum 25-hydroxyvitamin D concentration during winter in postmenopausal women in Greece, and in what degree it can contribute as a potential food-based strategy for the prevention of vitamin D deficiency. A secondary aim was also to investigate any potential effect of the intervention in several quality of life (QoL) indices in the population of postmenopausal women under study.

Vitamin D status in postmenopausal women is of interest because of the association of low vitamin D status with increased risk of osteoporosis and related fractures. In addition, since there is increasing evidence that the dietary supply is often insufficient to offset the seasonal deficit in sunlight during winter months, fortified food and supplements are becoming important sources of dietary vitamin D intake to achieve optimal vitamin D status, especially in this high risk population. Although most studies have examined the effectiveness of vitamin D enriched milk and yogurt, there have been limited studies also exploring the effectiveness of vitamin D enriched cheese in enhancing vitamin D status and preventing vitamin D deficiency. However, fortification of cheese with vitamin D has certain technological considerations, particularly for reduced-fat varieties considering that vitamin D is a fat soluble nutrient.

The primary aim of the current study was to investigate whether the consumption of vitamin D3 enriched, reduced-fat yellow cheese can counterbalance the expected decrease in serum 25-hydroxyvitamin D concentration during winter in postmenopausal women in Greece, and in what degree it can contribute as a potential food-based strategy for the prevention of vitamin D deficiency. A secondary aim was also to investigate any potential effect of the intervention in several quality of life (QoL) indices in the population of postmenopausal women under study. .

Inclusion Criteria:

• subjects are eligible if they are 55-75 years of age
• being at menopause for more than 5 years
• they used to consume cheese daily
• those with a Body Mass Index (BMI) range 20-33kg/m2

Exclusion Criteria:

• having any disease/ pathology that interacts with vitamin D metabolism
• taking medications that interact with vitamin D metabolism or vitamin D supplements for medical reasons (e.g. osteoporosis)
• planned vacation to a sunny holiday destination during the intervention period
• having a cow's milk allergy
• having a drugs and/or alcohol abuse