While it maybe true that you are not getting enough Vitamin D, cutting back on sunscreen is probably not the answer. Vitamin D is a critically important hormone that is required for healthy bones and maintaining blood calcium levels. Vitamin D also prevents osteoporosis, depression, many forms of cancer and acts to reduce blood pressure. A very small amount of vitamin D is obtained in the diet from oily fish but the vast majority is produced by the skin on exposure to ultraviolet (UVB) radiation from natural sunlight.
You need direct sun exposure to the skin to produce Vitamin D and even weak sunscreens (SPF=8) or glass will block the skin’s Vitamin D production. However, it is not necessary to sunbake as exposure of the hands, face and arms for around 10 minutes or just enough to produce a faint redness a few times a week will ensure you produce sufficient Vitamin D. Sun exposure in the middle of the day in summer is certainly not advised and sunscreen is still recommended to avoid sunburn.
Despite our climate, many Australians don’t get enough casual exposure to the sun to produce adequate amounts of Vitamin D. This is particularly true for elderly people, people who avoid the sun due to skin conditions and people with dark skin. Once produced in the skin, Vitamin D needs to be activated by the kidneys and liver to form the active form called calcitriol so people with diseases of these organs are at risk of Vitamin D deficiency. If sun exposure is not possible, a vitamin D supplement of at least 400 IU (10 μg) per day is recommended.