The body can only produce a certain amount of vitamin D at a time. So staying in the sun longer than necessary won't help increase your vitamin D levels, while it will increase your risk of skin cancer.
But it's difficult for people over 75 to get enough vitamin D from just a few minutes of sun exposure, so the Endocrine Society recommends that everyone 75 and older get 800 IU (international units) of vitamin D a day from food or supplements.
Why You Need More Vitamin D as You Age
In general, older adults also tend to have less exposure to sunlight, which is the main source of natural vitamin D. As we age, our skin becomes less efficient at synthesizing vitamin D from sunlight.
The kidneys and liver, which help convert vitamin D into its active form, also lose some of their effectiveness with age. This makes it harder for the body to maintain adequate levels of the vitamin.
Common deficiency in older adults
Despite their higher vitamin D needs, people over 75 may not get enough vitamin D.
Studies have shown that one in five older Australians are vitamin D deficient.
In higher latitudes around the world, such as the UK, almost half do not reach the required levels.
This increased risk of vitamin D deficiency is partly due to lifestyle factors, such as spending less time outdoors and a diet that does not provide enough vitamin D.
It's hard to get enough vitamin D from food alone. Fatty fish, eggs, and some mushrooms are good sources of vitamin D, but few other foods contain much of this vitamin.
Although foods can be fortified with vitamin D (margarine, some milks, and cereals), these foods may not be readily available or consumed in sufficient quantities to make a difference.
In some countries, such as the United States, most dietary vitamin D comes from fortified products. However, in Australia, dietary vitamin D intake is generally very low because only a small number of foods are fortified with vitamin D.
Why Vitamin D Is Important as We Age
Vitamin D helps the body absorb calcium, which is essential for maintaining bone density and strength. As we age, our bones become more brittle, increasing the risk of fractures and conditions such as osteoporosis.
Keeping your bones healthy is important. Studies have shown that older adults who are hospitalized for a hip fracture are 3.5 times more likely to die within 12 months than those who have not been injured.
Vitamin D may also help reduce the risk of respiratory infections, which can be more severe in this age group.
