Both sunscreen and margarine were invented long before you might think. Sunscreen was invented for cosmetic reasons, not health, by the ancient Egyptians. Margarine was created in 1869, not as a healthy substitute to butter but as a cheaper product made from beef fat. Margarine was widely viewed as unhealthy until after the 1950s when it started being touted as a health food. But, the pendulum is swinging back. We are beginning to recognize that butter may be better for us than highly processed margarine. Now, scientists are saying sunscreen might not be the best thing for our health.

Tracking results of a sunscreen PSA campaign that started in 1981, the Cancer Council Australia has seen melanoma levels drop, but they have also seen vitamin D deficiency rise. Having low levels of vitamin D impacts bone strength, increases the risk of infection, heart disease and cancer, makes the body less sensitive to insulin and more. Preventing skin cancer is incredibly important. But, what can be done about vitamin D? There are supplements. And, some foods are high in vitamin D. But, is that enough? The sun is the best source of vitamin D. Yet SPF 30 reduces the vitamin D produced by the body by 95-98 percent.

More than 40 percent of adults in the U.S. have a vitamin D deficiency. Very few foods contain a marked amount of vitamin D: swordfish, salmon, tuna, sardines, cod liver oil, beef liver and egg yolks. You would have to eat them daily for it to have an impact. Unless you’re a big fan of fish or offal, the diet would be hard to sustain. However, the good news is, cod liver oil has three times your daily recommended allotment of vitamin D in one tablespoon.

Some people are more resistant to absorbing vitamin D through the diet than sunlight. Your doctor may want to draw some blood to see how your vitamin D levels are. Vitamin D supplements should be taken with food as that aids absorption. Speak to your doctor about whether vitamin D supplements might help you.

In the UK, as little as 13 minutes in midday sun three times a week was enough for Caucasian adults to maintain healthy vitamin D levels. People with darker skin need more sunlight to keep their vitamin D levels healthy. People with darker skin have a heightened risk of vitamin D deficiency.

Spending too much time in the sun doesn’t just lead to cancer. It can cause eye damage, skin changes, sunburns, heatstroke and more. It may be a balancing act to get enough sunlight vs. protecting yourself from other ills. Speak to your doctor and come up with the best plan for your health, that fits your life.