Vitamin D: More Than Just a Sunshine Vitamin

By Ram Rao, Ph.D., Principal Research Scientist for Apollo Health

The advent of the winter season is marked by a deficiency of Vitamin D (Vit D) due to less outdoor activities resulting in poor exposure to the sun’s UV rays. Humans tend to spend less time outside during the colder months, which means less exposure to sunlight and heightened levels of Vit D deficiency. As cold and flu cases rise in the chillier months coupled with the continued presence of the COVID virus, we all need to be concerned about developing a weak immune system due to low Vit D levels.

Vit D, also known as the “sunshine vitamin” is a fat-soluble vitamin that is produced in the skin in response to sunlight and is required to keep our bodies functioning to their maximum potential. This fat-soluble vitamin belongs to a family of compounds that includes vitamins D-1, D-2, and D-3. In addition to sunlight-associated synthesis, Vit D is also obtained through certain foods and supplements. An optimal level of Vit D is necessary for overall growth and for improving immunity. The beneficial role of Vit D on the skeletal system by regulating the absorption of calcium and phosphorus has long been appreciated. Recent studies suggest that optimal levels of Vit D may (1) improve outcomes after a cancer diagnosis, (2)lower inflammation, and (3) reduce the risk of inflammatory diseases.

Chronic inflammatory conditions, including but not limited to inflammatory bowel disease, cardiovascular disease, asthma, chronic kidney disease, non-alcoholic fatty liver disease, neurodegenerative diseases, all feature low levels of Vit D. This suggests an inverse relationship between optimal levels of Vit D and the risk of ill-health and disease. A low Vit D status is also associated with increased risk and unfavorable outcomes of acute infections. There is also sufficient evidence to suggest a connection between low levels of Vit D and an increased risk of food-based allergies. Similarly, if you are experiencing high blood pressure, or if you’re trying to reduce your risk of diabetes, heart attacks, rheumatoid arthritis, multiple sclerosis, or Parkinson’s disease, then check your levels of Vit D and ensure that you have optimal levels of this important vitamin.

A growing body of epidemiological evidence suggests a close relationship between Vit D deficiency, Alzheimer’s disease, and cognitive decline. Vit D plays an important role in brain health and function and exerts various neuroprotective effects in brain areas essential for cognition. Low levels of Vit D are associated with a more than twofold increased risk of developing dementia. Subjects with low Vit D levels display slower information-processing speed, and this correlation is even stronger among subjects older than 60 years. Mechanistic studies now point to the role of Vit D in mediating the transcription of hundreds of genes involved in cellular processes such as neuroplasticity, the immune system, tumor formation, cardiovascular disease, and calcium regulation.

The most accurate way to measure the levels of Vit D is a blood test for 25-hydroxy vitamin D. While a level of 20 ng/ml to 80 ng/mL is considered normal for healthy people; it is advisable that your levels are in the optimal range (50-80ng/ml). If you’re diagnosed with a Vit D deficiency, you will need to improve the levels to ensure optimal levels of this vitamin. At Apollo Health we suggest the “hundreds rule to maintain optimal levels of Vit D”: subtract your current Vit D level from your target level, and multiply by 100 to determine your approximate dosage: for example, if your target is 70, and your current level is 20, then 70-20= 50, which means you need 5000 IU of Vit D per day.

The two main dietary forms of Vit D are D2, found in fungi and yeast, and D3, found in aquatic and land animals. Seafood including salmon, sardines, herring, mackerel (preferably wild-caught), red meat, egg yolks, and fortified foods (healthy dairy, fat spreads, and breakfast cereals) are rich sources of Vit D. Sun-dried, and UV radiation-exposed mushrooms are a rich source of Vit D and other essential vitamins, including vitamins B6 and B12. Vitamin D-enhanced mushrooms possess substantial amounts of bioavailable Vit D and are ideal for those following a flexitarian or plant-based diet. Taking your Vit D pills with some good fats (e.g., avocado, nuts, or fish oil) ensures maximum absorption.

In addition, remember, sunshine is the best medicine, so even if it is a cold, blustery day, step outside, get some sun, and improve your Vit D levels now and through the next year.