What is SPF? Everything you need to know about sunblock and how it works

What is SPF? Everything you need to know about sunblock and how it works

28 Jan 2022

Spending time outdoors is a big part of AUstralian culture, whether it be at the beach, playing at the park, or a bushwalk. That’s no surprise as being out under the sun allows the body to absorb vitamin D. It also aids the release of dopamine and the increase of serotonin uptake, thus improving our mood (1).

However, overexposure to the sun can cause severe damage to our skin (8). Ultraviolet (UV) rays are present in sunlight that reach the earth’s surface. The two types of UV rays you have to watch out for are UVA, which can cause premature skin ageing, and UVB, which causes sunburn and can contribute to formation of skin cancers (2).

How does sunscreen work

Sunscreen provides some protection against the harmful rays of the sun. But, how does sunscreen actually work?

How does sunscreen work?

Sunscreen is a lotion designed to protect our skin from the harmful effects of exposure to the sun’s UV rays.

There are 2 types of sunscreens: physical and chemical blockers.

Physical blockers are typically mineral-based type sunscreens that use zinc-oxide and titanium-oxide. These are designed to physically block harmful UV rays by reflecting them off the skin, preventing sunburn while it remains effective (3).

On the other hand, chemical blockers use chemicals like aminobenzoic acid, avobenzone octisalate, octocrylene, and oxybenzone that are absorbed by the skin and in turn absorb UV rays (4).

What is SPF?

Sunscreen usually comes with a sun protection factor (SPF) number. The SPF number tells you how long the sun’s UV radiation would take to redden your skin when using the product exactly as directed versus the amount of time without any sunscreen. So ideally, with SPF 30 it would take you 30 times longer to get sunburnt than if you weren’t wearing sunscreen (5).

It should be noted that sunscreen is not the all-in-one solution for skin protection against sunlight. Whilst it is recommended to protect your skin from UV rays, other skin protection practices should still be put in place. This includes physical protection from the sun’s rays like clothing or staying in the shade while the sun is out.

Vitamin supplements to aid in skin health

How does sunscreen work

Keeping your skin healthy also means making sure your body gets the nutrients it needs. While this is best done through a healthy diet, you may also consider taking supplements to ensure you achieve your daily requirements of these vitamins and minerals:


Our zinc supplement is in the form of zinc citrate which is one of the most easily absorbed forms and easily utilised by the body. There is growing clinical evidence about the role of zinc supplementation in supporting skin health (6). Zinc supports collagen formation, which promotes stronger skin.


Iron not only helps the immune system fight illness, but also supports collagen formation which is beneficial in maintaining skin health.

*Iron should only be taken if prescribed by your doctor.


Collagen maintains skin structure and integrity. In women especially, this protein supports the skin’s ability to maintain moisture as well as its firmness and elasticity, three things that give the skin a healthy, youthful appearance.


Astaxanthin is able to support healthy collagen formation.


Similarly, cranberry supports and maintains collagen formation in support of healthier skin.

Vitamins B complex and C

Studies show that Vitamin B Complex has the ability to support overall skin health, whereas Vitamin C also acts in support of collagen formation that is integral to skin.


Biotin plays a key role in enzymes for fatty acid synthesis (7). Skin cells depend on fatty acids to help produce the skin's natural oil barrier, providing protection from the sun and environmental toxins (9).

Sign up for a vitamin subscription box from Vitable Australia today to get tailored vitamins specifically for skin health and beyond. Have your daily vitamin packs brought to your doorstep through our vitamin delivery service.

Find out more about other areas that the above supplements can help you with:

Zinc | Iron | Collagen | Astaxanthin | Cranberry | Vitamin B complex | Vitamin C | Biotin

*Always read the label. Follow the directions for use. If symptoms persist, talk to your health professional. Vitamin and/or mineral supplements should not replace a balanced diet.


  1. Select Health. 7 Health Benefits of Sunlight. Published on https://selecthealth.org/blog/2020/07/7-health-benefits-of-sunlight. Accessed Nov 20, 2021.
  2. University of Iowa Hospital & Clinics. What is the difference between UVA and UVB rays? Published on https://uihc.org/health-topics/what-difference-between-uva-and-uvb-rays. Accessed Nov 20, 2021.
  3. Harvard Health Publishing. The science of sunscreen. Published Feb 15, 2021 on https://www.health.harvard.edu/staying-healthy/the-science-of-sunscreen. Accessed Nov 20, 2021.
  4. GraceMed. The Pros & Cons of Sunscreen. Published on https://gracemed.org/using-sunscreen. Accessed Nov 20, 2021.
  5. Skin Cancer Foundation. Ask the Expert: Does a High SPF Protect My Skin Better? Published June 9, 2020 on https://www.skincancer.org/blog/ask-the-expert-does-a-high-spf-protect-my-skin-better/. Accessed Nov 20, 2021.
  6. Julian-Dario Rembe, Carolin Fromm-Dornieden, Ewa Klara Stuermer. Effects of Vitamin B Complex and Vitamin C on Human Skin Cells: Is the Perceived Effect Measurable? National Library of Medicine. Published May 31, 2018 on https://pubmed.ncbi.nlm.nih.gov/29672394/. Accessed Nov 14, 2021.
  7. Zempleni, J., Wijeratne, SSK., Hassan, YI. 2009. “Biotin”. BioFactors, 35. Published 1 (Jan): 36-46. doi:10.1002/biof.8. Accessed Nov 14, 2021.
  8. Medline Plus. “Sun's effect on skin.” National Library of Medicine. n.d. Publisbed on https://medlineplus.gov/ency/anatomyvideos/000125.htm. Accessed Jan 4, 2022.
  9. Vitable Australia. “What are the effects of cosmetics on my skin?” Published Dec 28, 2021 on https://www.vitable.com.au/blog/what-are-the-effects-of-cosmetics-on-my-skin. Accessed Jan 4, 2022