Is Vitamin D From the Sun As Good As You Think?
Is Vitamin D From the Sun We all know that Vitamin D is important for the health of the bones and immune system, but are we getting enough of this important nutrient from the sun? According to Yale Medicine’s dermatologist, David Leffler, Vitamin D from the sun may not be as good for you as you think. The sun’s UVB rays may cause sunburn, but this type of UV radiation is beneficial to the body.
UVB radiation from the sun
Although the sun’s UVB rays are filtered, they can still damage our skin. In fact, even just 15 minutes of exposure can cause DNA damage. And that damage can continue for many years, resulting in genetic mutations that increase the risk of skin cancer. The most harmful UVB rays are received between 10 a.m. and 4 p.m., and about half of that radiation is harmful. The effects of sun exposure are even worse in children, where the risk of developing skin cancer is especially high.
The human body evolved near the equator and has developed a natural sunscreen – melanin. The absorption spectrum of melanin is 290-700 nm, allowing it to absorb solar UVB radiation. But Africans have very dark, heavily pigmented skin. Even with this protective layer of melanin, a small amount of UVB radiation can penetrate the skin’s epidermis and cause a rise in vitamin D3. Studies have shown that exposure to sunlight can increase blood vitamin D3 levels in white adults by 30 fold, while black adults did not raise their blood levels.
The quality of sun exposure is critical for the body to produce Vitamin D. The UVB rays are blocked by air pollution, clouds, sunscreen, and shade cast by buildings. Even more, aging lowers the precursor substance needed to produce vitamin D. Also, sunlight from a window is not able to produce vitamin D, since the glass and window block UVB rays. In addition, aging and pollution decrease the amount of the precursor substance needed to produce Vitamin D.
The solar zenith angle has a substantial impact on UVB radiation. Low angles require more distances through the ozone layer, increasing the probability of absorption and interaction with air molecules. This increases the likelihood of absorption and scattering back into space. The solar elevation also impacts the UVB spectrum. Therefore, the action spectrum of vitamin D is commonly referred to as the “action spectrum”. The maximum amount of vitamin D is observed at 295 nm.
Fatty fish
There is no scientific consensus on the best source of vitamin D for the human body, but it seems that most fish contain high levels of this vital nutrient. In fact, the content of vitamin D in fish varies widely among species. Therefore, it is vital to re-evaluate the traditional sources of vitamin D. Listed below are some fish that contain large amounts of vitamin D. These fish have relatively low fat content.
Pickled herring is a high-quality source of vitamin D, but it’s not ideal for people watching their sodium intake. Pickled herring contains 870 mg of sodium per serving, so it may not be the healthiest option. Canned sardines are another good source of vitamin D. The same goes for tinned or canned salmon. Both sources contain high levels of vitamin D, and you can even supplement your diet with cod liver oil.
Dried shrimp are another high-quality source of vitamin D. Dried shrimp are used as a spice in sea food soups and are great sources of protein. More studies on these products are needed to determine the best ways to incorporate them into new recipes. Dried fish is a valuable source of vitamin D, but lack of research has led to lower intakes. The main objective of this study was to determine the amount of vitamin D found in fishery products and explain the percent daily value of these products.
Moreover, vitamin D deficiency is a common global health problem, especially in countries with cold climates. Although most people get adequate vitamin D through diets, the levels vary by age, sex and fortification practices. However, fish is a vital part of the human diet and a valuable source of vitamin D3.
Supplements
Although the sun provides sufficient levels of vitamin D, some people may not be able to absorb the vitamin from the food they eat. This is particularly true of those with milk allergies or lactose intolerance, or people with dark skin tones. Vitamin D supplements are also beneficial for people with specific health conditions. A high-dose vitamin D supplement is not recommended for these people. However, there are other ways to obtain adequate amounts of vitamin D.
While there is no conclusive evidence to support the benefits of vitamin D supplementation, it is believed to help prevent many diseases. A recent meta-analysis revealed that low vitamin D levels are related to colorectal cancer, a condition that is often associated with the aging process. This study analyzed 5,700 colorectal cancer cases and concluded that low vitamin D levels were associated with a higher risk of developing this cancer.
Although vitamin D is not essential to a healthy diet, people who lack sunlight may benefit from taking a vitamin D supplement. The recommended daily amount of vitamin D is 600-800 IUs, but the VITAL study showed that 1000-2000 IUs per day can be safe. Vitamin D supplements can be obtained in the form of dark fatty fish, fortified dairy products, fortified orange juice, or multivitamins. Vitamin D supplements are safe for vegetarians, but they are not recommended for vegans.
In order to obtain sufficient amounts of vitamin D from sunlight, people must spend at least six months a year in places like Edmonton, Canada, and Boston, USA. In such places, it’s nearly impossible to produce vitamin D naturally. In addition, the ozone layer of the earth makes it difficult for the sun to penetrate the atmosphere and trigger a reaction that produces vitamin D. This explains why vitamin D supplements are needed in these places.
Skin pigmentation
Depending on the amount of skin pigmentation, people should adjust their daily vitamin D intake to prevent further skin pigmentation. This vitamin is produced in the skin by melanocytes, which need a certain amount of sunlight to produce the nutrient. Lighter skin types need fewer exposures to sunlight while dark skin types need more. According to your skin tone, you should adjust your sun exposure to get optimal results.
Serum 25(OH)D levels were associated with the degree of pigmentation and the amount of sun exposure. The proportion of children with vitamin D deficiency was based on the number of hours of sun exposure at the age of nine. The results of these studies showed that children with light skin had higher levels of vitamin D than those with darker skin. However, this association was small. The researchers concluded that vitamin D deficiency was uncommon among children.
Although the association between cutaneous melanin and vitamin D production is largely accepted by the scientific community, some authors have challenged this association. However, this finding is unlikely to be confirmed without further study. For now, we can conclude that vitamin D can help prevent skin pigmentation in a healthy and effective way. This is why it is critical to get adequate amounts of vitamin D. The skin pigmentation in our bodies depends on this hormone.
The Europeans, for example, were dark-skinned for 35 thousand years, and were only later able to get lighter skin through interbreeding with populations from outside their continent. But the advent of agriculture changed the diet composition to one that is low in vitamin D, thereby reinforcing selection pressure for light pigmentation. Likewise, the dark-skinned people of the Arctic have traditionally been explained by their marine diet.
Age
If you live in the southeastern U.S., you probably get your recommended daily allowance of vitamin D from the sun. Ten to 15 minutes on your face or arms is enough for optimum levels. It’s important to remember, though, that sunscreen blocks the UV rays of the sun, which are needed for the body to make vitamin D. But if you want to maximize the amount of vitamin D your body makes, you should use an appropriate sunscreen and get plenty of sunlight.
There are various guidelines for the amount of vitamin D people need. The normal level of vitamin D in the blood is twenty nanograms per milliliter. Adults and children aged between one and seventy years should aim to get at least fifteen micrograms of vitamin D per day. However, people with certain health conditions and those who are more vulnerable to vitamin D deficiency may need more. Vitamin D from the sun should be used carefully and as directed by a doctor.
The production of vitamin D decreases as adults age, and this decrease is accompanied by a decline in calcium absorption. The level of 1,25(OH)2D drops by as much as 50% when older, which is partially offset by secondary hyperparathyroidism. Age-related decline in vitamin D production precedes the reduction in calcium absorption by about 10 to 15 years. As a result, the vitamin D level in the blood can reduce even further if there is inadequate intake of the vitamin.
