Vitamin D is not one chemical but many. The natural type is produced in the skin from a universally present form of cholesterol, 7-dehydrocholesterol . Sunlight is the key: Its ultraviolet B (UVB) energy converts the precursor to vitamin D3. In contrast, most dietary supplements are manufactured by exposing a plant sterol to ultraviolet energy, thus producing vitamin D2. Because their function is almost identical, D2 and D3 are lumped together under the name vitamin D — but neither will function until the body works its magic ( see figure ).
Vitamin D is one of the 13 vitamins discovered in the early 20th century by doctors studying nutritional deficiency diseases. Ever since, scientists have defined vitamins as organic (carbon-containing) chemicals that must be obtained from dietary sources because they are not produced by the body’s tissues. Vitamins play a crucial role in our body’s metabolism, but only tiny amounts are needed to fill that role.
Vitamin D deficiencies were rare when most men rolled up their sleeves to work in sunny fields. But as work shifted from farms to offices, that changed. Because pigmentation can reduce vitamin D production in the skin by over 90%, nonwhite populations are at particular risk. Deficiencies are also common in patients with intestinal disorders that limit absorption of fat and those with kidney or liver diseases that reduce the conversion of vitamin D to its active form, calcitriol (1,25(OH)2D). In addition, certain medications reduce the availability or activity of vitamin D. And even in healthy people, advancing age is linked to an increased risk of vitamin D deficiency.
Vitamin D can be your good friend in menopause. Finding healthy ways to get enough may help you stay strong and prevent many age-related health problems.
Vitamin D is almost always needed with calcium. However, many (if not most) calcium formulas tend not to include D. In fact, most of the calcium formulas with D are the inorganic calcium carbonate forms, from rock powder or shells. These have the advantage of being rich in calcium and relatively low cost. The disadvantage is their poorer absorption, especially if there is low stomach acid present (this is common in seniors). The amount of Vitamin D in multiple vitamins is not likely to be enough to help absorb large doses of minerals.
Vitamin D deficiency causes a defect in the ability of the body to deposit calcium into the collagen jello-like matrix in the bone. As a result, the covering on the bone which contains pain sensing nerves is easily deformed resulting in throbbing aching bone pain. Patients with osteomalacia often complain of achiness in their muscles and bones. These non-specific aches and pains in the bones and muscles are often misdiagnoses as fibromyalgia or chronic fatigue syndrome. There have been several studies demonstrating that patients with severe bone and muscle pain and muscle weakness associated with osteomalacia have dramatic improvement in their symptoms when vitamin D deficiency is corrected. It takes months to years to develop osteomalacia and associated symptoms and it takes three to six months before significant improvement in symptoms results from correcting vitamin D deficiency.
Vitamin D deficiency will cause removal of both the calcium and matrix from the bone, and as a result, will cause osteopenia and can precipitate and exacerbate osteoporosis. Unlike osteomalacia which causes bone pain, osteoporosis, which is porotic bone, i.e., holes in the bones and loss of bone does not cause bone pain unless there is an acute fracture. Typically this pain resolves as the fracture heals and can be easily distinguished from osteomalacia.
Vitamin D supplements have no known side effects if supplements are taken at the appropriate dose. A dose of 4,000 IU/day has been identified as the tolerable highest dose a person can chronically consume without risk of adverse effects.
Vitamin D supplementation has been extensively studied as a treatment to prevent both falls and fractures. Research shows that vitamin D is an important factor in maintaining strong muscles and bones as it is an important nutrient involved in calcium metabolism, bone health, and muscle function. In addition, studies show that vitamin D may reduce the risk of cardiovascular disease and some forms of cancer, and may have positive effects on immune responses and anti-inflammatory benefits.
Vitamin D has been shown to have a positive effect on strengthening muscles, which play an important role in balance and mobility. It also helps maintain healthy bones, by assisting with the absorption of calcium into bones.