Vitamin D is frequently in the news lately. From babies receiving Vitamin D supplements to it being linked to many diseases including diabetes and osteoporosis. Everyone knows that Vitamin D is absorbed from the sun, but how, and why is it important? And if you have fair skin and burn easily, always needing to cover up – how do you get enough?
Vitamin D is a group of fat-soluble vitamins which are called secosteroids, or cholesterol-like substances. There are two major forms available – vitamin D2 (ergocalciferol) which is synthetic and vitamin D3 (cholecalciferol), which is the natural form found in animals, mainly fish liver oils. It’s also found in egg yolks, butter, mackerel, salmon, sardines and herring.
Vitamin D3 is manufactured in the body when the skin absorbs ultraviolet B light from the sun. Because its fat-soluble, it is processed by the liver, and the kidneys, to a form that can circulate through the body. The environment can affect how much vitamin D is absorbed, as clouds, rain, short winter days and excessive smog can reduce the body’s production of Vitamin D.
Why is Vitamin D Important?
It plays an important role in calcium metabolism, and severe Vitamin D deficiency can lead to rickets, a childhood disease that affects bone growth. It isn’t just for children though – adult bone turnover is also affected by vitamin D levels. It plays other roles in the body – important in many processes such as blood pressure regulation, maintaining energy levels, supporting muscle metabolism and regulating blood sugar levels.
Lack of vitamin D has been shown to affect mood levels – in areas in the far north, where winter days are short and sunshine lacking, sun lamps are often employed to combat SAD, or Seasonal Affective Disorder, which has been linked to low Vitamin D levels.
How To Get Enough?
Its important to be cautious when considering supplementation of Vitamin D, as with any Fat soluble Vitamin (E, A, F, K). Because it must be metabolized by the liver, its possible to overwhelm the body and experience a toxic level. Some of the symptoms of sun poisoning are possibly linked to excessive Vitamin D in the body. The Recommended Daily Allowance is usually between 200 and 600IU. Most supplements are in the range of 1000IU. Always check with your health care professional first, particularly if you suffer from issues with the kidneys or the liver.
The good news is that fish like salmon or sardines is high in Vitamin D and meets the daily required intake. These fish are also high in Omega 3’s, so enjoy!
Sources for this article include:
- Staying Healthy with Nutrition, Elson Haas