Fat Soluble Vitamins in Colostrum and Milk: Functional Micronutrient for Your Body

Vitamins are one class of micronutrient, the other being minerals. Vitamins are organic molecules(contain Carbon) while minerals are inorganic molecules.

Vitamins are not made in our body. Thirteen compounds or groups of compounds are recognized as vitamins. Vitamins can be water soluble or fat soluble vitamins. There are 4 fat soluble vitamins( A, D, E, K) and 9 water soluble vitamins(C and 8 B vitamins). The 8 B vitamins are B1(Thiamine), B2(Riboflavin), B3(Niacin), B6, Folate, B12, Biotin, Pantothenic acid.

Fat soluble vitamins are more stable to heat than the B vitamins, and less likely to be lost during food processing and cooking of food. They are absorbed from the intestines together with fats in food. If fat absorption is affected, then absorption of these vitamins is also affected. The fat soluble vitamins are first absorbed into the lymph system then into the blood. Most water soluble vitamins move directly into blood after absorption. Since fat soluble vitamins are not soluble in water, they are not soluble in blood. Thus, these vitamins require specific carrier proteins to transport them through the body.

Water soluble vitamins do not need carrier protein, and can travel freely. They are poorly retained by the body and need to be eaten regularly. Any excess is excreted in the urine. The fat soluble are not excreted in the urine. They are stored in the liver and fatty tissues until needed. Over supplementation of vitamins A and D can lead to their excess storage and toxicity. Milk and colostrum contains all the fat soluble vitamins A, D, E and K. The nature and health functions of these vitamins are described below.

Vitamin A is a family of fat-soluble compounds.

The three active forms of vitamin A in the body are retinol, retinal, and retinoic acid.

It is found as preformed retinol in animal sources and in food supplements. In plant-based foods, vitamin A is found in the form of provitamin A carotenoids, primarily as beta-carotene.

Vitamin A, as retinoic acid, can act as a hormone to affect gene expression and thus control cell development. Gene regulation by retinoic acid occurs in many types of cells and tissues in the body. In particular, it affects epithelial cells found in the lungs, trachea, skin, gastrointestinal tract, blood vessel walls, and the cornea. Vitamin A helps to maintain the normal structure and function of these epithelial cells.

Since vitamin A is required for the normal functioning of the retina, dim-light vision, and color vision, inadequate retinol and retinal available to the retina result in impaired dark adaptation.Vitamin A deficiency leads to excess deposition of bone-forming inorganic salts in the connective tissue inside the bones. Depletion studies have suggested that vitamin A is needed for the development and differentiation of white blood cells, such as lymphocytes, killer cells and phagocytes, which play a critical role in the body’s defense against pathogens.

Vitamin D can be synthesized in the human body from sun exposure. The active form of Vitamin D acts as a powerful hormone. Vitamin D is required to maintain the calcium and phosphorus balance in the body. The main dietary forms are vitamin D2 and D3 which become biologically active after conversion in the liver and then in the kidney. Vitamin D2 has the same biological activity as vitamin D3 and both compounds can be converted into active vitamin D.

Vitamin D is found in few foods. The richest natural sources of vitamin D are fish liver oils, and has long been successfully used for prevention and treatment of vitamin D deficiencies. Sardines, herring, salmon and mackerel are rich in vitamin D. Eggs, meat, milk and butter contain vitamin D in small amounts. Plants are poor sources, with fruit and nuts containing no vitamin D at all. The amount of vitamin D in human milk is insufficient to cover infant needs.Fortified foods provide most of the vitamin D, e.g., in America, low- and fat-free milks must be fortified by law with 100 IU per cup. Ready-to-eat breakfast cereals often contain added vitamin D.The primary role of vitamin D is to regulate calcium and phosphorus metabolism. Therefore, vitamin D contributes to the proper functioning of muscles and nerves, and plays a key role in bone formation and mineralization. Most of the calcium in the body is present in bone. However, calcium needs phosphorus to form the inorganic matrix of the bone called hydroxyapatite. The calcium and phosphorus used to be make bone are acquired from the bloodstream. Vitamin D is an essential part of the regulation of blood calcium and phosphorus.A drop in the blood calcium level is sensed by the parathyroid glands which then release parathyroid hormone. Parathyroid hormone stimulates production of an enzyme in the kidneys. This enzyme stimulates the conversion of inactive vitamin D into active vitamin D, calcitriol which increases blood calcium and phosphorus levels by stimulating absorption of calcium and phosphorus from food in the intestine. The kidneys also reduce losses of calcium and phosphorus in the urine in response to increased levels of calcitriol and parathyroid hormone. Parathyroid hormone and calcitriol also stimulate the release of calcium and phosphorus from the bones. All these actions help to keep the concentrations of calcium and phosphorus in the blood within stable levels, known as homeostasis. Excessive intakes are linked to abnormally high calcium levels in the blood and the deposition of calcium in soft tissues, such as connective tissues and blood.

Vitamin E includes two main groups of compounds: tocopherols (α-, β-, γ- and δ-) and tocotrienols (α-, β-, γ- and δ-).

α-Tocopherol is likely involved in strengthening certain aspects of cell-mediated immunity.Vitamin E deficiency can be caused by fat malabsorption disorders. Severe deficiency symptoms include peripheral neuropathy, muscle weakness, and damage to the retina of the eye.

The main function of α-tocopherol in humans is that of a fat-soluble antioxidant. Fats in cell membranes faced damage through lipid peroxidation by free radicals. α-Tocopherol can intercept free radicals to prevent a chain reaction of lipid oxidation. Limited clinical evidence suggests that vitamin E supplementation may help to manage age-related macular degeneration and fatty liver diseases secondary to type 2 diabetes mellitus.

Supplementation with α-tocopherol was found to slow cognitive decline in cognitively impaired subjects in some clinical studies.

Plant seeds, especially sunflower seeds, almonds, and hazelnuts, are rich sources of α-tocopherol. Many vegetable oils (e.g., olive oil and canola oil) also contain α-tocopherol. Other sources include tomato, avocado, spinach, asparagus,and broccoli.

Naturally occurring forms of vitamin K include phylloquinone (vitamin K1) and a family of molecules called menaquinones (MKs or vitamin K2). Vitamin K is the essential cofactor for biochemical processes that involved blood coagulation, bone metabolism, prevention of vessel mineralization, and regulation of various cellular functions. Vitamin K deficiency increases the risk of excessive bleeding or hemorrhage. Vitamin K deficiency may impair the activity of Vitamin K Dependent Proteins and increase the risk of osteoporosis and fractures. Overall, intervention trials are inconclusive regarding the role of supplemental vitamin K in further reducing bone loss in otherwise calcium- and vitamin D-repleted adults. Age-related cataracts may be the result of protein oxidation in the lens of the eye; α-tocopherol may protect the lens against oxidative damage from reactive oxygen species