Dubbed as the “Sunshine Vitamin”, vitamin D is produced when the skin is exposed to the ultraviolet (UV) light in sunlight. Vitamin D is essential in the maintenance of calcium homeostasis as it is responsible for absorbing calcium in the bones. However, vitamin D is not confined to the bone alone because receptors are present in nearly all the nuclei in the body and its actions are extremely diverse.
Here are some of the worst case scenarios when you don’t get enough of this vitamin.
Vitamin D is important in both phosphorus and calcium metabolism as it helps ensure the enough levels of these minerals for metabolic functions and mineralization of the bones. One effect of not having enough vitamin D is rickets. Up until the present, the deficiency in vitamin D is the major cause of rickets among infants in most countries. Studies by Pettiflor and his colleagues (2004) showed that climatic conditions that prevent ultraviolet exposure and low dietary intake of vitamin D can be attributable to such disease in toddlers. Interestingly, in sunny countries like Bangladesh and Nigeria, such occurrence of rickets is not well observed.
Chronic Muscle Pains
Vitamin D deficiency is associated with diffuse muscle pain and weakness as it exerts multiple effects on muscle health. Vitamin D deficiency can cause muscle atrophy of mainly type II muscle fibbers. Studies reveal that low vitamin D can cause general muscle pain and weakness, muscle cramps, chronic joint pain, and fatigue.
Vitamin D promotes bone health by maintaining the level of parathyroid hormones in a normal level. As a result, osteoblastic activity is stimulated, bone mineralization is promoted and risk of fracture is reduced (M.F., 2009). Hence, the lack of vitamin D in the body can lead to the occurrence of osteopenia and osteoporosis in adults. Chapuy et al.(1992) conducted several studies to evaluate the effect of vitamin D supplementation on the fracture risks. The results of their studies confirmed that with such supplementation with vitamin D, the number of hip fractures decreased by 43% and the total number of nonvertebral fractures by 32%.
In the Indian Journal of Endocrinological Metabolism, Lekha et al. (2013) have published that vitamin D is a potent inhibitor of keratinocytes and could be used safely for non-malignant hyper-proliferative skin disorders like psoriasis. Vitamin D aids in the absorption and distribution of calcium in the body. A recent finding by Gisondi (2012) proved that vitamin D deficiency is very frequent in patients with chronic plaque psoriasis. This finding was more common (i.e. 80% of cases) in winter, but it was found also in summer in approximately 50% of patients. The association between vitamin D insufficiency and psoriasis was confirmed independently of age, sex, BMI, PASI score, PTH and the season in which the serum sample was taken.
Several studies reveal that vitamin D deficiency leads to the increase acquisition of infectious diseases like tuberculosis and influenza (Martineau AR, 2007). This is highly related to the function of vitamin D which is the enhancement of innate immunity against various infectious diseases like tuberculosis and influenza. In the journal American Journal of Respiratory and Critical Medicine, Martineau published the effects of vitamin D supplementation in patients with active tuberculosis. The results of their study revealed that people who were supplemented had improved immunity against Mycobacteria, the causative bacteria of tuberculosis. Another related study was done by Urashima (2010), wherein they correlated vitamin D deficiency with the seasonality of epidemic influenza.
Vitamin D deficiency is also correlated positively with asthma and impaired lung function. Studies by Brown (2012) in the journal Dermatoendocrinology showed that there is a consistent association between vitamin D and asthma. Their study revealed that people who are less exposed to sunlight are more likely to have asthma attacks.
Several observational studies point to a strong association between Vitamin D deficiency and cardiovascular mortality. In the journal Annals of Family Medicine, Vitamin D deficiency has been reported to be associated with higher risk of metabolic syndrome, hypertension, and adverse cardiovascular events. In addition, severe Vitamin D deficiency not only increases the risk of developing cardiovascular diseases but also increases risk of sudden cardiac death.
Animal and human studies have suggested that vitamin D is a potential modifier of diabetes. Vitamin D has anti-inflammatory and immunodulatory effects. Published international studies that vitamin D deficiency is highly associated with the emergence and/or acquisition of diabetes mellitus. It has been found that vitamin D deficiency increase insulin resistance and decrease insulin secretion in type II diabetes mellitus.
Studies published in the Journal of the American Medical Association relate vitamin D deficiency to the risk of developing autoimmune diseases. One of them is by Munger (2006) which showed that people with less vitamin D in their body had increased risk for the development of multiple sclerosis. The study of Merlino et al. (2004) also showed that women, of ages 55-69, who have less exposure to sunlight or less intake of vitamin D had increased risk of rheumatoid arthritis.
Aside from the ones mentioned earlier, vitamin D plays a significant physiological role in the differentiation of normal and tumor cells. In the journal Cancer Epidemiology Biomarkers Prevention, Knight and his colleagues published their study about the effects of vitamin D deficiency on the emergence of breast cancer. The results of their study showed that living at higher latitudes with lower UV exposure increases the likelihood of breast cancer and of dying from them, as compared to living at lower latitudes. Vitamin D deficiency is also associated with the likelihood of colon cancers as shown in the results of the study of Palmer.
- Broe KE, C. T.-F. (2007). A higher dose of vitamin d reduces the risk of falls in nursing home residents: a randomized, multiple-dose study. J Am Geriatr Soc, 234-239.
- Brown SD, C. H. (2012). Vitamin D and asthma. Dermatoendocrinol, 137-145.
- Chapuy MC, A. M. (1992). Vitamin D3 and calcium to prevent hip fractures in the elderly women. N Engl J Med, 1637-1642.
- Fiscella K, F. P. (2010). Vitamin D, race, and cardiovascular mortality: findings from a national US sample. Ann Fam Med.
- Knight JA, L. M. (2007). Vitamin D and reduced risk of breast cancer: a population-based case-control study. Cancer Epidemiol Biomarkers Prev, 422-429.
- Lekha, R. K. (2013). Extraskeletal effects and manifestations of Vitamin D deficiency. Indian J Endocrinol Metab, 602–610.
- M.F., H. (2009). Vitamin D and health: Evolution, biologic functions, and recommended dietary intakes for vitamin D. Clin. Rev. Bone Miner. Metab, 2–19.
- Martineau AR, W. R. (2007). A single dose of vitamin D enhances immunity to mycobacteria. Am J Respir Crit Care Med, 208-213.
- Mathieu C, W. M. (1995). Prevention of type I diabetes in NOD mice by nonhypercalcemic doses of a new structural analog of 1,25-dihydroxyvitamin D3, KH1060. Endocrinology, 866-872.
- Merlino LA, C. J. (2004). Vitamin D intake is inversely associated with rheumatoid arthritis: results from the Iowa Women’s Health Study. Arthritis Rheum, 72-77.
- Munger KL, L. L. (2006). Serum 25-hydroxyvitamin D levels and risk of multiple sclerosis. JAMA, 2832-2838.
- Pálmer HG, L. M.-M. (2004). The transcription factor SNAIL represses vitamin D receptor expression and responsiveness in human colon cancer. Nat Med, 917-919.
- Pettifor, J. M. (2004). Nutritional rickets: deficiency of vitamin D, calcium, or both? The American Journal of Clinical Nutrition.
- Pilz S, M. W.-P. (2008). Association of vitamin D deficiency with heart failure and sudden cardiac death in a large cross-sectional study of patients referred for coronary angiography. J Clin Endocrinol Metab, 3927-3935.
- Urashima M, S. T. (2010). Randomized trial of vitamin D supplementation to prevent seasonal influenza A in schoolchildren. Am J Clin Nutr, 1255-1260.