This essential nutrient gets a lot of press but did you know these 5 surprising facts about the sunshine vitamin?
1. Sunscreen screens more than sunshine (say that 3 times fast…)
Did you know that being super strict with your sunscreen application may actually be hindering your exposure to vitamin D? We’re not suggesting you stop protecting your skin against UVB rays, but it’s important to know that sunscreen with a sun protection factor 15 or more blocks more than 99% of dermal vitamin D synthesis.
In fact, in Australia, it’s not a lack of sunshine that is contributing to a widespread vitamin D deficiency (over 30% of adults are deficient!), it’s been the strict application of sunscreen fueled by skin cancer scares. So a little bit of sun exposure can be healthy for us, just keep it under 20 minutes, and then pile on that sunscreen.
2. Obesity is linked to low vitamin D concentrations
There is a consistent association between obesity and low vitamin D concentrations, this is a one-way correlation as low vitamin D does not cause obesity.
Researchers have speculated that the fat-soluble vitamin D may become “trapped” inside fat tissue, so there is less available to circulate inside the body. The good news? Reports show that weight loss leads to increased vitamin D concentrations, which may in turn also provide additional protection against the plethora of chronic diseases associated with obesity.
3. Vitamin D has co-factors
How well vitamin D works depends on the levels of certain other vitamins and minerals present in the body, so it’s important you take care to have adequate levels of the following:
- Vitamin K: This vitamin has two types, K1 and K2. K1 is present in leafy green veggies like kale, chard and spinach. K2 comes from meats, particularly organ meats such as liver, eggs and hard cheeses.
- Magnesium: present in spinach, nuts, seeds, dark chocolate and whole grains.
- Zinc: oysters contain the most zinc, but it’s also found in red meat, poultry, crab and sesame seeds, pumpkin seeds and nuts like pecans, Brazil nuts and almonds.
- Vitamin A: brightly coloured fruits and veggies such as apricots, mango, carrots, kale and spinach.
4. Vitamin D lowers diabetes risk
By improving your sensitivity to insulin, the hormone responsible for regulating blood sugar levels, vitamin D reduces the risk of insulin resistance, which is a precursor to type II diabetes. Even if you have normal blood sugar today, a vitamin D deficiency makes you 91% more likely to progress to insulin resistance, or “pre-diabetes,” and it more than doubles your risk for progressing to active type. II diabetes.
5. Cooking impacts vitamin D content
Cooking methods impact the amount of vitamin D retention in foods. Vitamin D compounds in eggs baked in an oven for 40 min at normal cooking temperature showed retention at 39-45%, frying resulted in retention at 82-84% whilst boiled eggs were found to have a retention of 86-88%.
Oily fish is one of the best dietary sources of vitamin D. It’s worth investing in wild salmon which has an average of 500 – 1,000 IU of vitamin D per 100mg, compared to farmed salmon with an average of 100 – 250 IU of vitamin D per 100mg.
Article featured on the VITL blog