Summer is typically associated with abundant sunshine, outdoor activities, and a general sense of well-being. However, contrary to what many might believe, vitamin D deficiency can actually increase during this sunniest of seasons. Dr. Ghada Badri, Specialist-Internal Medicine at Thumbay University Hospital, provides insights into why this happens, the symptoms to watch for, and how to maintain optimal vitamin D levels.
Why Does Vitamin D Deficiency Increase in Summer?
Although summer provides ample sunshine, several behavioral factors can lead to an increase in vitamin D deficiency:
Indoor Confinement: To escape the extreme heat and avoid sunburn, many people prefer to stay indoors during peak sunlight hours. This behavior significantly reduces the time spent in the sun, limiting the skin’s ability to synthesize vitamin D.
Sunscreen Usage: Increased awareness of the harmful effects of UV radiation has led to more frequent and higher SPF sunscreen use. While protecting the skin from damage, sunscreen also blocks the UVB rays necessary for vitamin D production.
Symptoms of Vitamin D Deficiency
Residents should be vigilant for various symptoms that could indicate a deficiency in vitamin D. Common manifestations include generalized fatigue, muscle weakness, and bone pain. Fatigue can occur even in the absence of significant changes in calcium levels, highlighting the subclinical nature of early vitamin D deficiency. In severe cases, particularly in prolonged or severe deficiencies, individuals may develop hypocalcemia (low calcium levels) alongside low vitamin D levels. This condition can lead to osteomalacia, a softening of the bones characterized by bone pain, fractures, and muscle weakness, especially observed in elderly patients.
Natural Sources and Supplementation
Apart from sunlight exposure, there are limited natural dietary sources of vitamin D. One source is fortified dairy products, such as milk and yogurt, which are enriched with vitamin D during processing. Additionally, fatty fish like salmon, mackerel, and tuna contain small amounts of vitamin D. However, it can be challenging to obtain sufficient vitamin D from diet alone, particularly for individuals who spend most of their time indoors or live in conditions with restricted outdoor exposure.
Dr. Badri recommends oral vitamin D supplements for daily maintenance, typically ranging from 800 to 1000 international units (IU), and 400 IU for children. This dosage is prescribed to both men and women, considering factors like age, sun exposure, and dietary intake. For individuals who have limited sun exposure or are at higher risk of deficiency (such as older adults, or those with certain medical conditions), supplementation becomes particularly important to maintain optimal vitamin D levels. Regular monitoring and adjustment of supplementation under medical supervision is also needed to prevent deficiency-related complications.
Optimal Times for Sunlight Exposure
To safely get sunlight exposure without risking heat-related illnesses, Dr. Badri suggests going outside typically before 10 am or after 4 pm. During these times, the sun’s intensity is generally lower, reducing the risk of heat-related illnesses such as heat exhaustion or heatstroke.
Monitoring Vitamin D Levels
Routine testing every three months is often recommended for individuals with known or suspected deficiency. If initial tests reveal normal vitamin D levels, retesting may occur after six months to one year, depending on individual risk factors and clinical judgment. However, if vitamin D levels are found to be deficient, defined as less than 20 ng/mL, a treatment plan is advised. This plan may include vitamin D supplementation, tailored to the severity of deficiency and individual needs. After initiating treatment, it is crucial to recheck vitamin D levels approximately three months later to assess the effectiveness of the intervention. This follow-up ensures that the supplementation regimen is adequate to achieve and maintain optimal vitamin D levels.