Dietary Intake of Vitamin D from Dairy Products Reduces the Risk of Osteoporosis

Abstract

Background: Vitamin D and calcium are important dietary compounds that affect bone mass, even if other minerals (potassium, zinc, etc.) and vitamins (A, C and K) are also involved. Vitamin D and certain minerals, in fact, play an important role in calcium homeostasis and calcium absorption. Hip fracture incidence is higher in Europe and the United States, where calcium is frequently included in the human diet; while the occurrence of these fractures is lower in developing countries, where diets are often poor in calcium. This condition is named the “calcium paradox”, and may be partially explained by phosphate toxicity, which can negatively affect mineral metabolism. It is important to maintain correct dietary calcium-phosphate balance in order to have a healthy life, reducing the risk of osteoporotic fractures in older people. Vitamin D can also act as a hormone; vitamin D2 (ergocalciferol) is derived from the UV-B radiation of ergosterol, the natural vitamin D precursor detected in plants, fungi, and invertebrates. Vitamin D3 (cholecalciferol) is synthesized by sunlight exposure from 7-dehydrocholesterol, a precursor of cholesterol that can also act as provitamin D3. Dietary intake of vitamin D3 is essential when the skin is exposed for short periods to ultraviolet B light (UV-B), a category of invisible light rays such as UV-A and UV-C. This can be considered the usual situation in northern latitudes during the winter season, or the typical lifestyle for older people and/or for people with very white delicate skin. The actual recommended daily intake of dietary vitamin D is strictly correlated with age, ranging from 5 μg for infants, children, teenagers, and adults—including pregnant and lactating women—to 15 μg for people over 65 years.

Milk Consumption for the Prevention of Fragility Fractures

“…The potential bias by the corporate funding of trials or even speaker fees or travel grants should not be neglected [ 141 , 142 , 143 ]. Of 22 review articles (in English, found in PubMed by the search term “review AND (milk OR dairy) AND (osteoporosis OR fracture)” and limited to those papers with milk, dairy, or other dairy products in the titles published in 2016–2020) published in the past years, 13 papers [ 144 , 145 , 146 , 147 , 148 , 149 , 150 , 151 , 152 , 153 , 154 , 155 , 156 ] were written by at least one author with links to the dairy industry or dairy associations, whereas the authors of nine papers [ 4 , 9 , 10 , 157 , 158 , 159 , 160 , 161 , 162 ] did not report any such conflicts of interest. Although not explored, the proportion of opinion papers, comments, and letters to the editors with conflicts of interest is likely to be higher.…”

Association Between Vitamin D and Resistin in Postmenopausal Females With Altered Bone Health

“…With vitamin D deficiency, the risk of osteoporotic fracture is increased ( 18 ). In the current study, we found that around half of our postmenopausal females had either insufficient or had deficient levels of vitamin D. Several other studies in Pakistan found that most postmenopausal females were deficient in vitamin D levels ( 4 , 19 , 20 ).…”

The Role of Diet in the Pathogenesis and Management of Inflammatory Bowel Disease: A Review

“…Vitamin D is synthesised by UV exposure, with smaller amounts being derived from dietary sources such as oily fish and dairy products [ 87 ]. Vitamin D preserves and restores epithelial barrier function, in particular via promoting the expression of tight junction proteins [ 88 ].…”