Vitamin D Deficiency and the Factors: Are You Getting Enough Sunlight?

Vitamin D Deficiency and the Factors: Are You Getting Enough Sunlight?

Vitamin D Deficiency and the Factors:

Vitamin D is a bit different from the other vitamins, in that the primary source is the sun. Vitamin D is produced by the body in a complex process that starts when rays in the invisible ultraviolet B (UVB) part of the light spectrum are absorbed by the skin. The liver, and then the kidneys, are involved in the steps that eventually result in a bioavailable form of the vitamin that the body can use. Most foods are not a significant source of vitamin D and many doctors recommend taking 800 IU or higher of vitamin D3 a day There are many factors that can affect a person's vitamin D levels. 




Vitamin D and Black Skin: 

Vitamin D insufficiency is more prevalent among people of colour - Africans, Caribbean, (blacks) in general than any other race in the western world. Figures suggests 75% of people in the US are deficient in vitamin D, including 95% of African Americans. These figures have climbed dramatically since the early 90s, when fewer than half the country needed to rely on vitamin D supplements for their health.

Most young, healthy blacks do not achieve optimal vitamin D concentrations at any time of year. This is primarily due to the fact that pigmentation reduces vitamin D production in the skin. Also, from about puberty and onwards, vitamin D intakes of blacks are below recommended intakes in every age group, with or without the inclusion of vitamin D from supplements.

Despite having low levels of vitamin D, blacks have lower rates of osteoporotic fractures, at least among younger individuals. Research is showing that vitamin D protects against other chronic conditions, including cardiovascular disease, diabetes, and some cancers, all of which are as prevalent or more prevalent among blacks than whites. Clinicians and educators should be encouraged to promote improved vitamin D status among blacks (and others) because of the low risk and low cost of vitamin D supplementation and its potentially broad health benefits.


There are many factors that can affect a person's vitamin D levels:

  • Spending more time indoors: Your body can't make vitamin D if you're sitting indoors by a sunny window because ultraviolet B (UVB) rays (the ones your body needs to make vitamin D) can't get through the glass. Spending more time indoors than outside, your skin is not being exposed the sun.


  • Not getting enough magnesium: Because magnesium assists in the activation of vitamin D. Without sufficient magnesium levels, vitamin D can't be metabolised. If you're deficient in magnesium, vitamin D remains stored and inactive in your body, and you won't get its benefits. 
  • Gut Health: The vitamin D that is consumed in food or as a supplement is absorbed in the part of the small intestine immediately downstream from the stomach. Stomach juices, pancreatic secretions, bile from the liver, the integrity of the wall of the intestine — they all have some influence on how much of the vitamin is absorbed. Therefore, conditions that affect the gut and digestion, like celiac disease, chronic pancreatitis, Crohn's disease, and cystic fibrosis, can reduce vitamin D absorption.
  • Malabsorption: people who have undergone resection of the small intestine are at risk for this condition; diseases associated with vitamin D malabsorptioninclude celiac sprue, short bowel syndrome and cystic fibrosis. Certain medications and drugs also effect vitamin D absorption, check with your Doctor to find if your medication may affect with Vitamin D 
  • Sunscreen: In our fear of skin cancer are we actually blocking out the sun's benefit? Sunscreen prevents sunburn by blocking UVB light and may also lower the process of the body making adequate vitamin D levels. While it is preached to people to protect themselves against skin cancer, there are healthy, moderate levels of unprotected sun exposure that can be very helpful in boosting vitamin Using sunscreen with an SPF of 15 or higher can reduce the body's vitamin D production by 99 per cent.

  • Stress: During periods of acute stress, Vitamin D stores are used up. Additionally, most people when extremely stressed out or ill, are not spending a lot of time outdoors, depleting vitamin D further. Vitamin D deficiency increases your risk of illness from viral infections.
  • Skin colour: Melanin is the substance in skin that makes it dark. It competes for UVB with the substance in the skin that kick-starts the body's vitamin D production. As a result, dark-skinned people tend to require more UVB exposure than light-skinned people to generate the same amount of vitamin D.
  • Skin temperature:Warm skin is a more efficient producer of vitamin D than cool skin. So, on a sunny, hot summer day, you'll make more vitamin D than on a cool or cold day. 
  • Age: Compared with younger people, older people have lower levels of the substance in the skin that UVB light converts into the vitamin D precursor, and experimental evidence shows that older people are less efficient vitamin D producers than younger people. Between middle-age and older age vitamin D levels may decline.

  • Liver & Kidney Health: Some types of liver disease can reduce absorption of vitamin D because the ailing liver isn't producing normal amounts of bile. With other types, steps essential to vitamin D metabolism can't occur — or occur incompletely. Levels of the bioactive form of vitamin D tend to track with the health of the kidneys, therefore someone with kidney disease, bioactive vitamin D levels decrease as the disease gets worse, and in end-stage kidney disease, the level is undetectable.
  • Your weight: Fat tissue absorbs vitamin D and stored and can be a source of the vitamin when intake is low, or production is reduced. But studies have also shown that being obese is correlated with low vitamin D levels and that being overweight may affect the bioavailability of vitamin D.
  • Cold Climates: At higher latitudes, the amount of vitamin D–producing UVB light reaching the earth's surface goes down in the winter because of the low angle of the sun. In the winter season in the UK and Europe sunlight doesn't contain enough UVB radiation, little if any vitamin D is produced in people's skin tissue from October through March. Short days and clothing that covers legs and arms also limit UVB exposure.

  • Pollution:Carbon particulates in the air from the burning of fossil fuels, wood, and other materials scatter and absorb UVB rays. Ozone absorbs UVB radiation, so holes in the ozone layer could be a pollution problem that winds up enhancing vitamin D levels.


How long to be out in the sun:

People with dark skin, such as those of African, African-Caribbean or south Asian origin, will need to spend longer in the sun to produce the same amount of vitamin D as someone with lighter skin. On average around 1 hour or more a day for dark skin people exposing enough skin to the sun. 

Lighter skin people can make enough vitamin D from being out in the sun daily for short periods with their forearms, hands or lower legs uncovered and without sunscreen. On average 15-20mins a day. The lighter you are the quicker you absorb Vitamin D. Be careful not to burn in the sun, take care to go in the shade, cover up or protect your skin with sunscreen before your skin starts to turn red or burn. 


TIP: Ask your Doctor for a blood test to see where your vitamin D levels fall. Based on the results, they’ll be able to provide a recommendation of a safe dose of a vitamin D supplement that is right for you. Also, fat-soluble vitamins, like vitamin D, need to be taken with a meal with fat in it to absorb properly, e.g., coconut oil etc.


Further Readings:

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