Vitamin D deficiency stems from a combination of factors limiting the body's ability to obtain and utilize sufficient vitamin D. This can be due to insufficient intake, limited sun exposure, impaired kidney function, or poor absorption.
Key Causes of Vitamin D Deficiency:
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Insufficient Dietary Intake: Consuming insufficient amounts of vitamin D-rich foods or not taking supplements can lead to deficiency. Many foods are naturally low in vitamin D, and fortification levels vary across regions.
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Limited Sun Exposure: Sunlight is crucial for vitamin D synthesis in the skin. Factors such as living in higher latitudes with less sunlight, using sunscreen consistently, or spending minimal time outdoors can significantly restrict vitamin D production. This is especially relevant for people with darker skin pigmentation, which requires more sun exposure to produce the same amount of vitamin D as lighter skin. (Source: https://ods.od.nih.gov/factsheets/VitaminD-HealthProfessional/)
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Kidney Dysfunction: The kidneys play a vital role in converting vitamin D into its active form, calcitriol. Kidney disease or impairment can hinder this conversion, resulting in deficiency even with adequate vitamin D intake or sun exposure. (Source: People can develop vitamin D deficiency when usual intakes are lower over time than recommended levels, exposure to sunlight is limited, the kidneys cannot convert 25(OH)D to its active form, or absorption of vitamin D from the digestive tract is inadequate.26-Jul-2024)
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Poor Absorption: Certain medical conditions, such as malabsorption syndromes (e.g., Crohn's disease, celiac disease), can interfere with the gut's ability to absorb vitamin D from food or supplements. (Source: People can develop vitamin D deficiency when usual intakes are lower over time than recommended levels, exposure to sunlight is limited, the kidneys cannot convert 25(OH)D to its active form, or absorption of vitamin D from the digestive tract is inadequate.26-Jul-2024)
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Other Factors: Additional factors that increase the risk of vitamin D deficiency include obesity, certain medications (such as corticosteroids), and advanced age. (Source: https://www.webmd.com/diet/vitamin-d-deficiency) The risk also varies by race and ethnicity; for instance, non-Hispanic Black individuals have higher rates of deficiency than others. (Source: https://ods.od.nih.gov/factsheets/VitaminD-HealthProfessional/)
Consequences of Vitamin D Deficiency:
Vitamin D deficiency can lead to various health problems, particularly affecting bone health. In children, it causes rickets, characterized by bone softening and deformities. In adults, it can contribute to osteomalacia (softening of bones) and osteoporosis (bone loss), increasing fracture risk. Other symptoms include muscle weakness, fatigue, and pain. (Sources: https://medlineplus.gov/vitaminddeficiency.html, https://www.yalemedicine.org/conditions/vitamin-d-deficiency)
