Vitamin D is just as important to adults as it is to children, it is a unique vitamin for two reasons: it´s synthesized by the body when the skin is exposed to sufficient sunlight; and because it´s involved in regulating the function of specific organs.
Vitamin D is scarce in nature but you can find it in fish with many amounts of oil in the flesh (salmon, sardines and herring among others).
Vitamin D´s primary function is to enhance intestinal absorption of calcium and phosphorus in order to maintain adequate blood levels of the two minerals for calcification of bone and cartilage. Therefore it prevents Osteomalacia and Osteoporosis.
Classic symptoms of vitamin D deficiency
The early signs are irritability and restlessness. A kid with rickets walks or crawls late and the cranial fontanels are delayed in closing. One of the first unmistakable signs is a soft, yielding skull. The ribs will bend and the ends of the long bones will swell. Mechanical and gravitational stress will eventually cause bowed legs, knock knees, depression in the chest and pigeon-chest deformity of the rib cage. In rachitic children, the teeth erupt late, decay early and are malformed. Low blood levels of calcium may also result in neuromuscular hyperirritability, spasms of the wrist and food, general spasticity and convulsive seizures.
When vitamin D deficiency occurs in adults, the bones are robbed of their minerals. This demineralization is usually more severe in the spine, pelvis and legs. The bones of the spine soften and compress, the long bones bow and the pelvis compresses. These deformities result in pain and the pain is aggravated by muscle strain, weight bearing, pressure or sudden movements. Narrowing of the brith canal, scoliosis and shortening of the spine can also occur. Muscle weakness in the lower limbs may lead to a waddling pace.
Osteomalacia and osteoporosis are often confused. Osteoporosis also involves demineralization of the bones but rather than softening, the bones become porous and brittle. Osteoporosis not only occurs with old age or menopausal changes, recent research indicate that dietary calcium and vitamin D are also important factors.
Adequate vitamin D (and calcium) can prevent osteoporosis.
A British study revealed a definite association between spontaneous fractures in the long bones of people suffering rheumatoid arthritis and a deficiency of vitamin D.
Bone demineralization usually begins between the ages of thirty and forty, so the above information is not of the interest only to the elderly. Doctors have suggested that dietary changes made before demineralization starts will help prevent the process from ever occurring.
Vitamin D and Kidney Disease
Many of the symptoms of renal failure are similar to those of vitamin D deficiency. Since the kidneys are essential to the metabolism of vitamin D, researchers have suspected that some of the symptoms actually do result from a metabolic deficiency of the active form of the vitamin.
SOURCES OF VITAMIN D
Natural sources of vitamin D are scarce, unless you include sunshine. Fish, especially fish with heavy amount of oil in the flesh (saltwater fish, salmon, sardines and herring) are good sources. Liver, egg yolk and summer milk are also good sources.
Source: Dominik Bosco´s People´s guide to Vitamins and Minerals; from A to Zinc