Straining your eyes? You can listen to this automated AI version of the article here:
Spring and the longer daylight hours may be just around the corner; however, with reduced sunlight hours during the winter months, you could be suffering from a vitamin D deficiency. Some key symptoms can include achy bones, feeling down – the ‘winter blues’, head sweating and gut trouble.
- More like a Hormone than a Vitamin
- Immune Support
- Heart Health
- Mood and Depression Support
Best known for its role in supporting bone health and strengthening the immune system, vitamin D is essential for maintaining the mineral balance within the body and has a much wider role to play in our overall health. Read on to discover a few of the less well-known benefits of vitamin D.
More like a Hormone than a Vitamin
Regarded as “the Sunshine Vitamin”, between 80-100% of the recommended vitamin D level is produced within the skin. Cholesterol is converted to 7-dehydrocholesterol, which is then converted to cholecalciferol upon adequate exposure of the skin to UVB radiation from sunlight. Both ingested (cholecalciferol) and absorbed forms are then converted with the help of the liver and the kidneys into calcitriol – the active form of vitamin D. Calcitriol has the typical structure of other steroidal hormones such as oestrogen, cortisol, and aldosterone, making it behave more like a hormone, than a vitamin. Diet alone can be an adequate source if you consume plenty of fatty animal foods. This is how humans in the Artic obtained their vitamin D3. Naturally produced Cod liver oil is especially rich in vitamin D3 and Vitamin A in the correct ratio but it is difficult to get a cold-processed cod liver oil that has not had the natural nutrients removed and synthetic nutrients added – check with the manufacturer.
Low vitamin D levels have been linked to an increased risk of lung issues, autoimmunity, and increased infections. Research suggests vitamin D may help to support the function of the lungs and reduce the incidence of upper respiratory tract infections. Vitamin D receptors are expressed on immune cells, which can synthesise the active metabolite, calcitriol, highlighting its critical effect on the immune system.
Vitamin D deficiency has been linked to an increased risk of cardiovascular dysfunction. Vitamin D is well-known for its ability to stimulate the absorption of calcium; this is believed to be one of the factors that may contribute to the protective effect on the cardiovascular system, as calcium is essential for heart muscle function. Be aware that adequate Vitamin K2, from grass-fed butter and cheeses, animal fats, liver, egg yolks, and natto, for example, is critical in order to “direct” calcium to where it needs to go, and K2 deficiencies have been linked to calcification of soft tissue in the cardiovascular system.
Blood Sugar Support
Vitamin D deficiency is suggested as one of the contributing factors in the development of blood sugar imbalances. Inadequate vitamin D, may affect the release of insulin, reduce insulin-producing cell function, and impair glucose metabolism in the body. Healthy insulin release is essential for the regulation of blood sugar levels in the body.
Mood and Depression Support
Increasingly, research is finding a possible link between vitamin D and its effect on neurotransmitters such as serotonin, which has a large influence on our mood, sleep, stress and overall well-being. Increased vitamin D levels can be effective in helping to manage symptoms of low mood, and there is also a suggested link between reduced sunlight exposure during winter and the development of the “winter blues”.
Your environment and lifestyle choices can affect your body’s ability to produce vitamin D. As the majority of vitamin D is produced from exposure to adequate sunlight, people who actively avoid the sun by covering their skin, have a dark skin tone, or live at a latitude that has limited UVB in the winter months, can be at greater risk of deficiency.
Increasing outdoor activities and exposing your skin to unprotected sunlight are helpful ways to ensure you are getting enough vitamin D. Because it is fat-soluble, vitamin D is stored in our body (chiefly in the liver) and so “stocking up” in the summer can often cover your needs for the winter; however, it is important, particularly during summer, to be very careful when exposing our skin to the sun and for only short periods to avoid sunburn. Before 10am and after 4pm are safer, when UV conditions are lower. Check with an app like D-Minder for when there is sufficient UVB from the sun in your area. Supplementing your diet with vitamin D can also be a convenient and easy way to ensure you are consistently getting the required daily dose of vitamin D, especially during those darker winter months.
What are the different types of Vitamin D, and what are their bodily functions?
Vitamin D3, cholecalciferol, is the type we can obtain from animal foods and from the conversion of cholesterol in our skin via exposure to UVB; and vitamin D2, ergocalciferol, is mainly obtained from mushrooms that have been exposed to sunlight. D2 is poorly converted in the body to calcitriol; therefore, is not a good source of vitamin D. Calcitriol is the active form of vitamin D in the body. Calcitriol regulates calcium and phosphorus absorption for healthy bone growth and maintenance and is involved in cell growth and nerve function, and healthy immune function.
What are some natural sources of Vitamin D?
While sunlight is the most efficient way for the body to produce Vitamin D, several natural food sources contain cholecalciferol (D3), including fatty fish, egg yolks, cod liver oil, raw dairy fat, cheese, and liver.