The “Sunshine Vitamin”
After years of being told that we need to slather on the sunscreen – many Americans are now low in Vitamin D levels. A study published in 2009 in the Archives of Internal Medicine, found that 70% – 97% of Americans have insufficient blood levels of Vitamin D – a contributing factor to osteoporosis, linked to a recent rise in bone fractures, and even associated with several different types of cancers and other disorders.
Vitamin D is not really a vitamin, but a pre-hormone produced in the skin after exposure to the sun’s UVB light. Very few foods in nature contain significant amounts of natural vitamin D. The flesh of fatty fish (such as salmon, tuna, and mackerel) and fish liver oils contain vitamin D – cod liver oil is one of the richest food sources of vitamin D, with 1,360 IU per tablespoon. However, according to Dr. Andrew Weil, “some kinds of cod liver oil provide as much as 13,500 IU of vitamin A, and that’s way too much.” Some foods are fortified with vitamin D, such as milk. But the best source by far is the sun, which is why it is called the “Sunshine Vitamin.” Another surprising food that can contain vitamin D is button mushrooms. Button mushrooms that are exposed to UV rays absorb vitamin D, similar to our skin. But most mushrooms are grown in shade, so they will not have vitamin D. So you want to look on the label to see if the mushrooms you get contain vitamin D. The brand Monterey Mushrooms contains 400 IUs of vitamin D per 3 oz. serving.
Vitamin D is critical for calcium absorption – which is why low levels of vitamin D can be associated with rickets, increased risk of fractures, and osteoporosis. People taking calcium supplements should make sure they have sufficient vitamin D levels because calcium that is not properly absorbed can end up in places where it is not wanted – like the arteries of the heart, leading to hardening of the arteries. Read more about vitamin D’s role in calcium absorption. Low levels of vitamin D have also been linked to heart disease, some cancers, diabetes, immune disorders, insulin resistance, and more.
Am I Vitamin D Deficient?
The symptoms of vitamin D deficiency can be subtle, they include:
- Chronic pain
- Muscle weakness or soreness
- Bone fractures
- Hormonal imbalances
- Periodontal disease
- Rickets in children and osteomalacia in adults
Some people with low vitamin D may not have any symptoms at all. If you suspect that you are not getting enough vitamin D, a blood test can check your vitamin D levels, ask your doctor for a 25-hydroxyvitamin D, or 25(OH)D, test. Read “Am I Vitamin D Deficient?” for more information. Your healthcare practitioner can order the test and advise you on the best ways to increase your vitamin D. If you do decide to take a vitamin D supplement – it should be vitamin D3 (cholecalciferol). According to the New England Journal of Medicine, vitamin D deficiency is defined as circulating levels of 25-hydroxyvitamin D that are less than 32 ng per milliliter. Many studies suggest that optimal blood serum levels are around 50 ng/ml.
How Much Vitamin D do we Need?
The daily recommended doses for vitamin D maintenance were revised in 2010:
- Under age 1: 400 IU
- Under 70 years of age: 600 IU
- 71 years and older: 800 IU daily
- Pregnant and lactating women: 600 IU
However, it is important to get a blood test to assess your vitamin D levels because people who are seriously vitamin D deficient could require a short course of a high dose vitamin D3 supplement to build up their serum levels. This is something that should happen under a doctor’s care – as it is possible to get too much vitamin D, which can be toxic to the body.
The Sun’s Rays – Harmful or Healing?
In excess, the sun’s rays can harm, but in small doses, they can heal – providing the best source of vitamin D. But how much sun light is enough? According to the Vitamin D Council, the amount of sunlight you need to obtain enough vitamin D depends largely on the pigment of your skin. Approximately 10-15 minutes of unprotected sunlight a couple of times a week might be enough for fair-skinned people (after that people that continue to be out in the sun should apply sunscreen). Persons with darker skin will need more exposure because they do not absorb the sun’s rays as quickly. The torso absorbs the sun the best followed by the arms/legs, whereas the face and hands absorb the least. So people wanting to limit the aging effects of the sun on their face & hands, can shade the face from the sun or apply sunscreen to the face/hands – and get their sun exposure from the torso/arms/legs. Using sunscreen with an SPF as low as 8 can block as much as 95% of vitamin D production says the Vitamin D council.
The body converts enough vitamin D3 from the sun, long before a sunburn occurs. According to John Cannell MD, Executive Director, Vitamin D Council, “Humans make thousands of units of vitamin D within minutes of whole body exposure to sunlight.” And another cool thing about getting your vitamin D from the sun – is that it is free! But some people won’t want to risk getting any unprotected sunshine – they can supplement with Vitamin D3. Even people who get some sunshine might need to supplement.
Some smart sunscreen companies are now adding Vitamin D3 into their sunscreens, check out Ocean Potion, many of their sunscreens now contain Vitamin D3, so you can protect your skin while getting vitamin D!
Read Eat Your Sunscreen to learn more about boosting the body’s own internal SPF.
If you are interested in more information, the following articles contain excellent information:
*This content is not to be construed as providing medical advice. All information provided is general and not specific to individuals. Persons experiencing problems or with questions about their health or medications, should consult their medical professional. Persons already taking prescription medications should consult a doctor before taking the above foods, herbs, vitamins or supplements to be sure there are no interactions.
©2011, all rights reserved. Sara Vance.