Sunshine – friend or foe?

By Hilde Nel

With all the new information available on the importance of vitamin D, questions about the safety of sun exposure are receiving newfound attention.


Until recently, many people considered the sun to be an enemy that must be avoided at all costs. The focus was mainly on the aging effects of sunburn and the increased risk of skin cancer. Sunblock creams with unrealistically high sun protection factors flew off the shelves. The chemical content of these creams was often ignored.

Clearly, concerns about skin cancer are relevant. The ozone is thinning, and dangerous radiation is filtering through the thin layer that shields us. On the other hand, the advantages of exposing ourselves to correct and safe levels of sunshine are making headlines.

A primary benefit of sun exposure is mood elevation. Our emotions are energised by the sun. We need its warmth and brightness to light up our minds. Instead, our indoor lifestyle results in Seasonal Affective Disorder (SAD). This condition causes depression and lethargy, especially during winter months.

The Canadian Cancer Society recommends taking at least 1,000 IU vitamin D per day for SAD.

Most of us rely on sunshine for our daily dose of vitamin D. But, owing to our indoor lifestyle, most South Africans have a false sense of security concerning optimal vitamin D levels. Even in sunny South Africa, our indoor lifestyle spells danger.

Vitamin D’s role in disease prevention

Nearly every tissue in our bodies contains receptors that are stimulated by vitamin D. Vitamin D functions as a hormone in our bodies that affects most organ systems.

  • Weak bones

Vitamin D is well known for its role in bone-building. It facilitates the absorption of calcium into the bones.

  • Cancer

Several studies have shown that vitamin D reduces the risk of breast, colon, prostate and lung cancer, among others. In some studies, the reduction was between 60% and 77%.

A team of cancer prevention specialists at Moore’s Cancer Centre at the University of California, San Diego found that women with the highest vitamin D levels in their blood had the lowest risk of breast cancer, while those with the lowest levels had the highest risk. Vitamin D seems to control cell differentiation.

A June 2019 analysis of 10 trials involving 79,055 participants found that people who took vitamin D3 supplements had a 13% lower risk of dying from cancer than the placebo group.

  • Arthritis, muscle pain and muscle weakness

Chronic inflammation is an underlying factor in many conditions, such as arthritis, chronic muscle pain and muscle weakness. Vitamin D seems to decrease pro-inflammatory cytokines.

In 2007, a controlled trial in 124 nursing home residents (average age: 89) found that those taking 800 IU of supplemental vitamin D had a 72% lower fall rate than those taking a placebo.

  • Auto-immune conditions

In auto-immune conditions, the body’s immune system attacks its own cells. Examples of such conditions include rheumatoid arthritis, multiple sclerosis, type 1 diabetes, psoriasis and lupus. Studies at Harvard Medical School found that vitamin D alleviates the symptoms of multiple sclerosis.

  • Cardiovascular disease

Recent research highlights vitamin D’s significant role in the prevention of heart disease. Preliminary research shows that correcting vitamin D deficiency may be important for decreasing the risk of high blood pressure.

  • Diabetes

Vitamin D deficiency is particularly dangerous for those with type 2 diabetes. It seems that vitamin D affects insulin secretion and glucose tolerance in diabetics.

Risk factors for vitamin D deficiency

  • Indoor lifestyle – many of us spend most of our days indoors
  • Obesity – vitamin D is deposited in body fat stores, making it less bio-available in obese people
  • Aging – elderly people have a reduced capacity to synthesise vitamin D
  • Inflammatory bowel disease – conditions such as Crohn’s disease increase the risk of vitamin D deficiency
  • Sunscreens – using a sunscreen with an SPF factor of 8 reduces the production of vitamin D in our skin by a staggering 95%
  • Skin colour – dark-skinned people do not synthesise vitamin D optimally from sunshine and must therefore consider supplementation.

A note of caution

  • Vitamin D can interfere with the action of calcium channel blockers
  • Vitamin D toxicity can cause hypercalcemia, which could cause kidney stones, bone loss and calcification of soft tissue over time
  • Vitamin D must be taken 2 hours away from cholesterol-lowering medication.

The verdict

Exposing ourselves to healing sunshine is crucial. But we must do it responsibly. It’s all about balance – avoiding the sun is just as dangerous as over-exposure. Focus on shorter periods of sun exposure but wear protective clothing or an all-natural sunblock when you must stay in the sun for extended periods.

If safe sunbathing is not possible, take a good vitamin D supplement to prevent the development of serious health conditions. Don’t miss out on one of the most far-reaching discoveries of our time!

References available on request