Updated: Mar 15, 2021
Vitamin D has been in the news a lot recently after being linked to bad outcomes in people with SAR-CoV-2 (covid or corona virus), so much so that the British government are going to give free vitamin D to the elderly and those it considers "vulnerable". Low levels of the vitamin have been common in people that develop a bad case of covid, that end up needing hospitalisation. The thought is that, because Vitamin D is vital to the immune system, low levels of this vitamin lead to a weakened immune system that cannot fight off the virus and causes people to become very ill.
What Is Vitamin D
Vitamin D isn't actually a vitamin at all, it's a hormone and it helps to keep bones, teeth and muscles healthy. It does this by regulating the amount of calcium and phosphate in the body. Vitamin D deficiency can lead to bone deformities such as rickets in children, and bone pain caused by a condition called osteomalacia in adults. For the immune system, vitamin D helps to regulate the immune system by getting the cells of the immune system to behave in the way that they are meant to. Each type of immune cell, of which there are 5, neutrophils, eosinophils, lymphocytes, basophils and monocytes each have a different job to perform. If even one of these cell types stops functioning correctly your whole body is put at risk.
Vitamin D is made in the skin of many animals using ultraviolet radiation from the sun, this includes humans, rats, pigs, horses, poultry, sheep and cattle. Some animals, such as cats and dogs don't produce a lot of vitamin in their skin, they get most of it from their diet. For animals that have very little skin exposed to the sun, like chickens, vitamin D is made in their feet. One of the problems with this is that you need to get enough ultraviolet radiation to make vitamin D. Along the equator there is ultraviolet all year round, but as you move away from the equator there is less. The rule is that, on a sunny day, if your shadow is taller than you are the light isn't the right kind for your skin to use, leaving your body to rely on vitamin D that it has stored. People with darker skin or are wearing a high factor sunscreen will make hardly any vitamin D at all; this also applies on cloudy days. This means that people in huge areas of the world are vitamin D deficient.
Supplementing With Vitamin D
Vitamin D can be found in several foods, most of them are animal products, such as eggs and red meat, however, the amount of vitamin D in these foods is low, it is not enough to keep you healthy. Fortified foods, such as breakfast cereals are a good source, they contain higher levels of the vitamin and you also know exactly how much you are getting with each serving. The safest way to ensure that you are keeping your vitamin levels topped up, without visiting a doctor, is to use supplements. There are 2 types of vitamin D supplement that you can buy, D3 and D2. D3, cholecalciferol, is made by animals in their skin, intestines and other body parts using cholesterol. Vitamin D2, ergocalciferol, is only made by plants, however, we can't get our vitamin D2 from eating plants, we can only get enough from supplements. Vitamin D3 in supplements is usually made from lanolin extracted from sheep's wool, the use of this wool means that D3 is not vegan and should be avoided. Vitamin D2 is suitable for vegans as it is plant based, the only problem is that this form of vitamin D is less effective at raising levels within the body, so more may be needed to achieve healthy vitamin D levels but this is easily done by adjusting doses or buying a higher concentration tablet, spray or capsule.
As with vitamin B12 vitamin D is massively important to our bodies and good health. Most doctors advise that everyone should supplement with some form of the vitamin, it takes huge doses to reach levels that would make you ill, that would be toxic. However, it doesn't take much to become deficient and have problems with bone and muscle pain as well and this is before more serious health problems begin. Take a look at your local health food store or get on the internet to find out what is available to you.