“A recent BMJ study has suggested that there may be benefit in [vitamin D] reducing respiratory tract infections, but the jury is still out,” he wrote. “There are large scale randomized controlled trials due to report in a number of health outcomes that should give us a clearer idea in the next two to three years.”
Goodman says that this BMJ study, which shows a link between vitamin D levels and immune system health, could be a game-changer.
“Our bodies are producing cancer cells all the time, but what happens is our immune system detects that there’s an alien cell and it destroys it, just as it would destroy a bacterium — and it does not work properly without vitamin D,” she said. “I see particularly low levels of vitamin D in my patients with breast cancer.”
She suggests that anyone who has had cancer, particularly breast cancer, should have their levels checked immediately.
Goodman also suggests a link between healthy vitamin D levels and brain function, telling Healthline, “You’ve got to remember that the brain is a fatty organ … All the nerve cells are basically coated in a myelin sheath, which is basically fat.”
She emphasized that people need their fat-soluble vitamins, particularly vitamin D.
Get it checked
Multivitamin supplements may promise a well-rounded nutritional regimen, but they often don’t deliver, said Goodman.
“I definitely do not recommend multivitamins,” she said. “Firstly, they tend to have tiny amounts of everything, and secondly, they tend to have lots of fillers and rubbish in them.”
Some options may have too much vitamin A, and many use a cheap, synthetic form of vitamin D, called vitamin D-2, according to Goodman.
“Vitamin D-3 is the real thing. It’s what our body makes from sunshine. Multivitamins really are a cheap substitute for eating properly,” she added.
It’s worth noting that the body cannot create vitamin D if it doesn’t have the necessary components to do so. “One of the causes of vitamin D deficiency, especially in women, is low-fat diets,” said Goodman.
People who don’t have enough fat in their diets won’t get enough vitamin D because it’s a fat-soluble vitamin, she explained
Goodman closed with this advice for keeping your vitamin D levels up during the winter months: “Eat oily fish — that is, salmon, trout, mackerel, sardines, and so on — through the winter, make sure you’re getting as much sunshine exposure as you can, and if you’re poorly, get your vitamin D levels tested.”