Vitamin D - The Sunshine Vitamin
As I woke up one morning and placed my feet on the ground, I found my ankle had a cracking ache, the one you know that is linked to your bones. A thought passed my mind, aging bones do require more of bone strengthening vitamins and minerals-such as Calcium, Vitamin D and the ones linked to their absorption.
Maybe I was not taking enough of them. Vitamins and minerals are two of the main types of nutrients that we need to live and stay healthy. When these are deficient in our diet or are not being utilized properly in the body, some specific deficiency symptoms occur. When the deficient nutrient is resupplied before irreversible damage occurs, the signs and symptoms are reversed.
What are Vitamins?
Vitamins are organic compounds found in very small amounts in food and are required for metabolism, protection, maintenance of health and proper growth. In general, vitamins cannot be synthesized by the body, and humans depend on their diet to supply them. However, certain vitamins can be synthesized in the body to some extent, such as vitamin D that is produced when the skin is exposed to sunlight; niacin which can be synthesized from the amino acid tryptophan; and vitamin K and biotin are synthesized by bacteria living in the gut. Vitamins help our body to grow and work the way it should.
There are 13 vitamins—vitamins A, C, D, E, K, and the B vitamins (thiamine, riboflavin, niacin, pantothenic acid, biotin, B6, B12, and folate).
Types of Vitamins
Vitamins can be classified according to their ability to be absorbed in fat or water. The solubility of a vitamin influences the way it is absorbed, transported, stored, and excreted by the body as well as where it is found in foods. Fat-soluble vitamins are absorbed with fats and oils in foods and in the body and require protein carriers for transport through the water-filled compartments of the body and are stored in fatty tissues and/or the liver. As you can see with the image below, fat-soluble vitamins include vitamin E, vitamin A and its precursor beta-carotene, vitamin K and vitamin D.
Water-soluble vitamins are absorbed directly into blood where they travel freely and do not require protein carriers. These are not stored in body, but tissues can be “saturated”. Water-soluble vitamins include vitamin C and the B-complex vitamins, including the lesser-known biotin and pantothenic acid, as well as vitamin B6 (pyridoxine), vitamin B12 (cobalamin), thiamine (vitamin B1), folate, niacin (vitamin B3) and riboflavin (vitamin B2).
Functions of Vitamins
Vitamins have different jobs—helping us fight infections, keeping our nerves healthy, and helping the body get energy from food or our blood to clot properly. By following a healthy balanced diet, wel get enough of most of these vitamins from food.
Poor bone health can cause conditions such as rickets and osteoporosis and increase the risk of breaking a bone from even a minor fall .A healthy balanced diet from early life will support building of strong bones and in maintaining them throughout life. Many nutrients play a role in bone health. Calcium, vitamin D and magnesium are key bone health nutrients that require special attention to ensure that we meet our daily requirement.
Vitamin D - why is it a sunshine vitamin?
Vitamin D is a unique vitamin. It is made from the cholesterol in our skin when exposed to sunlight. It is essential for strong bones as it helps our body to absorb calcium from our diet.
Deficiency of Vitamin D is said to be linked with osteoporosis and arthritis, where bones tend to weaken with age. Vitamin D (Calciferol), comprises of a group of fat-soluble sterols found naturally in few foods and is known as the sunshine vitamin. The two major physiologically relevant forms of vitamin D are D2 (ergocalciferol) and D3 (cholecalciferol).
Doctors also recommend adolescents and young adults to include enough vitamin D-rich foods in their diet to promote better bone health. It has been roughly estimated that ultraviolet-B (UV-B)-induced production of vitamin D in the skin accounts for about 80% of vitamin D supply, whereas dietary intake (e.g. fish, eggs or vitamin D-fortified food) plays usually only a minor role .
The Groups at Risk of Vitamin D Inadequacy
Breastfed infants, Older adults, women who are past menopause, people with limited sun exposure, people with conditions that limit fat absorption, people with dark skin, people who are obese or have undergone gastric bypass surgery.
Vitamin D inadequacy and health
Deficiency of Vitamin D, besides being related to weak bone health, is also linked to different other deficiency diseases, such as
Frequent illness or infections: Vitamin D helps in regulating immune function and inhibiting inflammatory reactions. It can also help prevent infections in the upper respiratory tract.
Muscle weakness and fatigue: vitamin D is key to bone health, an insufficient amount can cause bone and muscle weakness, which can lead to fatigue.
Bone, joint and back pain: This might be the most easily recognizable symptom of vitamin D deficiency. A dip in the in-body stores of vitamin D, can cause bone, joint and back ache. Further, it can decrease the bone mass and lead to bone loss, especially in women as they age.
Fractures: Adequate vitamin D in the body helps maintain bone strength by supporting the absorption of calcium. Bones become weaker when they start to lose more calcium and absorb less of it.
Depression: lower levels of vitamin D may increase the risk of depression. Being one of the integral parts of brain receptors, lack of it might cause a breakdown in their functioning and deteriorate brain health.
Slow wound healing. Vitamin D plays an important role in wound healing because it regulates growth factors and other compounds that form new tissue. Therefore, slow wound healing can be an indication of a vitamin D deficiency.
Vitamin D deficiency in children can cause-irritability, lethargy, bone pain or fractures, deformities of the teeth and developmental delays.
Rickets and Osteomalacia: Vitamin D is critical for bone and mineral metabolism and is effective in the prevention and treatment of rickets and osteomalacia. Rickets, a disease in which bone tissue doesn’t mineralize, leads to soft bones and skeletal deformities that affects the development of the bones, wrists, knees, and joints in the ribs, and can cause bowing of the legs. In adults it is manifested as osteomalacia. Moreover, deficiency can cause severe asthma in children and cognitive impairment in adults.
Vitamin D is a natural immune modulator, and studies support that it could play a role in prevention of autoimmune diseases, including type 1 and 2 diabetes, multiple sclerosis, rheumatoid arthritis, Crohn’s disease. Besides, low vitamin D levels are linked to other conditions that increase the risk of developing cardiovascular disease — conditions such as hypertension and metabolic syndrome.
Vitamin D: Sources
Vitamin D is fat soluble, which means you need to eat fat to absorb it. Foods high in vitamin D include Fatty fish, egg yolks, liver oil, shrimps, oysters. Egg yolks can also be high in vitamin D, especially if the chickens are free-range. For a vegetarian, the sources are limited to mushrooms exposed to sunlight, yogurt, or curd, milk, and milk products, from cows grazing in outdoor range.
To get enough vitamin D, one needs to eat some of these foods daily. Manufacturers add vitamin D to many commercially available foods. These are known as fortified foods, for instance, fortified milk, fortified milk substitutes, fortified yogurt, margarine, fortified breakfast cereals, fortified fruit juice, eggs etc.
Sunlight - the best source of Vitamin D
It is difficult to obtain sufficient vitamin D from natural food sources alone. If one’s diet does not provide sufficient amount of this vitamin, it is recommended to take vitamin D supplements and get some sun to maintain the optimal levels in the body. Sunlight is said to be the best source of vitamin D. As Vitamin D is made from cholesterol in the skin, one must expose lots of skin to sunlight to get enough of this. Exposure to sunlight typically between 1000 h and 1500 h in the spring, summer, and in the autumn/fall between 30 minutes to 1 hour with 40 percent skin exposed, will help meet the Vitamin D requirements.
Vitamin D deficiency is common, and people may not realize that they have it.
Anyone with symptoms of the deficiency should see a doctor. Many people have no or subtle symptoms but can find out if they have adequate levels with a simple blood test. Even without symptoms, low levels of Vitamin D can pose health risks.
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