Seasonal shifts in weather bring increased focus on immune health, with internal medicine specialists highlighting the roles of vitamins C and D in defending against upper respiratory infections.
As temperatures drop and time spent indoors increases, maintaining balanced nutrient levels becomes a priority for managing seasonal health risks. Experts and health centers say supporting the immune system is important for the winter months.
Vitamin C and D Roles in Immunity
Internal Medicine Specialist Dr. Özkan Akyol said that C and D vitamins are central to a strong immune system during autumn, according to reporting from Habertürk. Dr. Akyol explained that vitamin C supports the body’s natural defense mechanisms to increase resistance against the common cold, while vitamin D acts as a key component for the healthy function of immune cells.
Despite their importance, Dr. Akyol cautioned against viewing these vitamins as individual solutions, noting that "the excess can be as problematic as the deficiency," as reported by Habertürk. He emphasized that vitamin D levels often decline during autumn due to reduced exposure to sunlight, particularly among those working in indoor settings.
Prof. Dr. Canan Karatay highlighted the broader systemic importance of these nutrients, noting that vitamin C supports white blood cells, which she described as the body’s protective soldiers. "As you know, leukocytes, or white blood cells, are our protective soldiers. But this doesn’t happen when there’s a vitamin C deficiency." said Prof. Dr. Canan Karatay, as reported by Türkiye Gazetesi.
She added that vitamin C also helps lower histamine levels in the body, thereby reducing allergic reactions.
Balancing Intake and Natural Sources
While supplementation is an option, Dr. Akyol recommended that vitamin D levels be assessed through a simple blood test before starting any regimen. For vitamin C, he said that natural intake is efficient, suggesting that individuals consume citrus fruits, kiwifruit, broccoli, and green peppers to meet daily requirements, according to Habertürk.
Karatay claimed that high sugar intake can prevent vitamin C from entering cells, stating, "When there is sugar, vitamin C cannot enter the cell. Sugar locks the door," as reported by Türkiye Gazetesi. Karatay also advised against using effervescent products, preferring pure ascorbic acid mixed with water. She further said that low levels of vitamin C are linked to a higher incidence of resistance to antibiotics.
Lifestyle Factors for Winter Health
Beyond vitamin intake, medical guidance suggests that a comprehensive approach to health is necessary for winter preparation. Dr. Akyol highlighted that regular sleep, a balanced diet, and physical activity are as essential as vitamin supplementation for protecting against upper respiratory infections, as noted by Habertürk.
Their approach includes specific lifestyle habits such as thorough chewing—recommending 30 to 40 chews per bite—and limiting raw food consumption to before 4:00 p.m. to support digestive efficiency, according to Haberton.
Fructose and Sunlight Exposure Affect Vitamin Levels
Professor Dr. Canan Karatay claims that fructose in fruit juice and refined sugars can compete with or block vitamin C from entering cells, effectively limiting its availability to the body, as reported by Türkiye Gazetesi.
Dr. Özkan Akyol said that individuals who spend most of their time in indoor environments are at a higher risk of experiencing a drop in vitamin D levels due to the lack of adequate sunlight exposure during the autumn months.
The VIVAMAYR center suggests maintaining a gap of 4 to 5 hours between meals, avoiding water consumption during or immediately after meals, and eating evening meals early to support digestive health, as reported by Haberton.
"Let’s not forget that a strong immune system is the most important guarantee of a healthy winter." said Dr. Akyol.