December 21st officially marks the darkest day of the year, and although it means lighter days are ahead, there are still many gloomy weeks to get through. Self-care is particularly important to combat seasonal depression.
Beyond the mental aspect, the lack of sunlight means there may also be reason to stock up on supplements, particularly vitamin D. While most vitamins can be absorbed from a balanced diet, vitamin D is naturally present in very few foods.
Unless you eat plenty of fatty fish and fish liver oil, you may be deficient outside the summer months. Did you know that the worldwide prevalence of vitamin D deficiency is as high as 1 billion? In the US, about 42% of the population is vitamin D deficient, with a concerning rate of 82% in Black people and 70% in Hispanics.
The “sunshine vitamin” plays a vital role in calcium homeostasis, skeletal metabolism, and immune, cardiovascular, and reproductive systems’ functions. Not getting enough vitamin D may cause muscle weakness, intensify bone loss, and increase the risk of fractures. Several epidemiologic studies also support an association between vitamin D deficiency and increased breast cancer risk.
The National Institutes of Health (NIH) recommends an average daily intake of 10–20 micrograms, or a slightly higher intake if you aren’t being exposed to the sun much at all, or have a darker skin tone. Especially in winter, make sure you get your daily dose as an additional step in lowering your breast cancer risk.
Source
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5802611/