Vitamin A is a family of fat-soluble compounds, which plays an important role in vision, bone growth, reproduction, cell division, and cell differentiation. According to National Institutes of Health (NIH), Vitamin A is important for healthy bones. Vitamin A is found in two forms: retinol and beta carotene. Retinol or “true” Vitamin A, as it is sometimes called, is practically ready for use by the body. Retinol is found in such animal foods as liver, eggs, and fatty fish. Since Vitamin A is stored in the liver, the liver of animals and fish is particularly rich in Vitamin A. Retinol can also be found in many fortified foods, such as breakfast cereals, and in dietary supplements. Beta-carotene is a precursor for Vitamin A. The body needs to convert it to retinol or Vitamin A for use. Beta-carotene is found naturally in mostly orange and dark green plant foods, such as carrots, sweet potatoes, and mangoes. The antioxidant properties of beta carotene play a protective role in ensuring good bone health.
A water soluble vitamin, Vitamin C is essential for collagen formation and normal bone development. Collagen is the main structural protein of connective tissues. Vitamin C is also an important anti-oxidant. All fruits and vegetables contain some amount of Vitamin C. According to NCBI, positive association between higher intake of fruits and vegetables and skeletal health has been suggested to be partly attributable to Vitamin C. Rich sources of Vitamin C are citrus fruits and juices, such as orange and grapefruit, kiwi fruit, mango, papaya, pineapple, strawberries, raspberries, blueberries, cranberries and watermelon. Among vegetables, broccoli, cauliflower, green and red peppers, spinach, cabbage and other green leafy vegetables and tomatoes are rich in Vitamin C.
Vitamin K is present in the liver and other body tissues, including the brain, heart, pancreas, and bone. A fat soluble vitamin, Vitamin K functions as a coenzyme for Vitamin K-dependent carboxylase, an enzyme required for the synthesis of proteins involved in blood clotting and bone metabolism, and other diverse physiological functions. According to research studies by NCBI, it plays an important role in bone health.8 NIH states that deficiency of the clinically significant Vitamin K in adults is very rare and is usually limited to people with malabsorption disorders or those taking drugs that interfere with Vitamin K metabolism. The main sources of Vitamin K are leafy green vegetables such as dandelion greens spinach, Swiss chard, lettuce, cabbage, kale, cauliflower, broccoli, and Brussels sprouts. The absorption is greater when accompanied by fats such as butter or oils; some fruits, such as avocado, kiwifruit and grapes are also high in Vitamin K. According to NIH, most people get Vitamin K from green vegetables, and dark berries. Intestinal bacteria also produce small amounts of another type of Vitamin K.
There is a significant association between bone density and intake of Mg, an essential micronutrient with a wide range of metabolic, structural and regulatory functions. An adult body contains approximately 25 gm Mg, with 50 to 60 percent being in the bones and most of the rest in soft tissues. Less than 1 percent of the total Mg is found in the blood serum, and these levels are kept under tight control. Research studies by NCBI have found that low Mg intake retards cartilage and bone differentiation as well as matrix calcification with deficiency contributing to development of osteoporosis. Mg deficiency indirectly impacts bones by affecting the homeostasis of the two master regulators of calcium homeostasis, i.e., parathyroid hormone and Vitamin D, thus leading to hypocalcemia. Green vegetables, nuts, seeds, unprocessed grains and some legumes contain large amounts of Mg.
Phosphorous is an essential mineral and plays an important role in bone mineralization. Phosphate is the most abundant anion in the human body and comprises approximately 1 percent of total body weight. The majority of phosphate is found in bones and teeth (85 percent), with the remainder distributed between other tissues (14 percent) and extracellular fluid. The main food sources are protein food groups (meat and milk). According to the NCBI, the presence of phosphate is crucial for bone growth and mineralization and insufficient amounts lead to development of skeletal diseases.