Vitamin winter deficiency

Vitamin D deficiency results from insufficient intake, decreased sun exposure, decreased skin production, decreased fiver and renal metabolism, and winter residence in northern climates. 

Lack of sunlight. Exposure to sunlight can provide sufficient vitamin D. However, in latitudes greater than 40° north or south vitamin D winter deficiency can occur. People with dark skin can suffer deficiency especially if their skin is completely covered and they live in the northern or southern latitudes previously mentioned. Such people, for example Muslim women living in northern Europe, can be hypocalcaemic. 

Vitamin D deficiency is associated with higher rates of pneumonia infection of both viral and bacterial origin. In vitamin D-deficient Ethiopian children under the age of five, a thirteen-fold increased risk of pneumonia was evident compared to vitamin D-suffident case control subjects (Muhe et al. 1997). Half of the children hospitalized for pneumonia in a series from Yemen were rachitic (Banajeh et al. 1997). Forty-three percent of rachitic children in Kuwait had pneumonia (Lubani et al. 1989). An association of subcUnical vitamin D deficiency with marked acute lower respiratory infection was also evident in Indian children younger than five years old (Wayse et al. 2004). As mentioned previously, an association between serum vitamin D concentrations <40 nmol/L and acute respiratory tract infection was found as well in young Finnish military recruits (Laaksi et al. 2007). In a prospective cohort study of 198 healthy adults, mouthly serum 25(OH)D was measured and participants were evaluated for any form of respiratory tract infection by investigators blinded to 25(OH)D status (Sabetta et al. 2010). Maintenance of a serum concentration of 38 ng/mL or higher afforded a reduction in the incidence of acute viral respiratory tract infections, especially during the fall and winter. 

The vitamin C deficiency disease, scurvy, was formerly a common problem at the end of winter, when there had been no fresh fruits and vegetables for many months. 

We noted above that small amounts of ultraviolet light are required for the activation of vitamin D. This interesting reaction occurs by a [1,7] suprafacial rearrangement. Vitamin D is a necessary part of the human diet for bone growth. Inadequate amounts of this vitamin result in inadequate calcification of bones. This condition in children is called rickets. The disease in adults is called osteomalacia. In spite of a dietary vitamin D deficiency, it is known that an individual may generate vitamin D since sunlight can activate a Vitamin D precursor. But in northern climates where the days are short in the winter, and one s skin is covered, it is not possible to produce enough vitamin D to make up for dietary deficiencies. 

Vitamin D deficiency is a serious menace to children living in northern latitudes, and especially dwellers in crowded areas, where the sunlight available in the winter months is insufficient to synthesise the vitamin from body sterols. 

Ascorbic acid, or vitamin C, was discovered after scientists had searched for centuries for a cure for the disease known as scurvy. The name ascorbic acid comes from word anti-scurvy acid, because it was known to dramatically cure this disease. This disease was caused by a serious deficiency of vitamin C, and it caused its victim s small blood vessels to rupture, bones to weaken, and joints to swell, among other symptoms. These symptoms were due to the fact that without a source of vitamin C one developed severe problems concerning the body s connective tissues, which is found in bones, skin, muscles, teeth, blood vessels, and cartilage. This disease would eventually lead to death if it went untreated, and was not uncommon, especially during the winter months of the year. The disease often plagues armies, explorers, and crusaders, since these men s diets normally consisted of biscuits and salted meat that could easily be stored and kept unspoiled on a ship. 

Vitamin D is responsible for maintaining calcium homeostasis. Low calcium concentrations lead to hyperparathyroidism and bone resorption. Vitamin D insufficiency (11 to 20 ng/mL) and deficiency (<10 ng/mL) [25(OH) vitamin D measurement, 10 ng/mL = 25 mcmol/L] is becoming more commonly recognized in all age groups, ° especially malnourished individuals, northerners, women wearing veiled dresses, African-Americans, seniors, and long-term care residents. Low vitamin D concentrations resnlt from insufficient intake, decreased sun exposure, decreased skin production, decreased liver and renal metabolism, and winter residence in northern climates. 

Add supplements to your diet. With so little exposure to sunlight in winter, our bodies may become relatively deficient in vitamin D. Some studies have shown benefit from adding vitamin D to the diet of SAD sufferers, so try adding 600 mg to 1000 mg of vitamin D3 to your daily diet during the winter. Also take B-complex vitamins and essential fatty acids as described in Chapter 5. 

Various factors can cause a deficiency of sunlight and therefore of vitamin D3, including ones geographic latitude and the season of the year. Sunlight levels are lower in extreme northern and southern latitudes, and are much lower in winter, so much so that for these conditions dietary guidelines in many countries call for supplemental D3 for children and older persons. Other factors that can affect vitamin D3 production in the skin are skin coloration, cloud cover, and the use of sunscreens. 

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