According to a Scientific Advisory Committee on Nutrition (SACN) new guidelines, children and adults over the age of one should have 10 micrograms (mcg) of vitamin D every day.
In a change to previous advice, SACN is now recommending:
- a reference nutrient intake (RNI) of 10 micrograms of vitamin D per day, throughout the year, for everyone in the general population aged 4 years and older
- an RNI of 10 micrograms of vitamin D per day for pregnant and lactating women and population groups at increased risk of vitamin D deficiency
- a ‘safe intake’ of 8.5 to 10 micrograms per day for all infants from birth to 1 year of age
- a ‘safe intake’ of 10 micrograms per day for children aged 1 to 4 years
- The RNI and safe intakes were developed to ensure that the population has enough vitamin D to protect musculoskeletal health, all year round.
SACN did not take account of sunlight exposure in making recommendations because of the number and complexity of factors that affect skin synthesis of vitamin D.
The RNI and safe intakes refer to intake from all dietary sources:
- Natural food sources: Wild-caught fish (425 IU in 3 oz salmon, 547 IU in 3 oz mackerel), Beef or calf liver (42 IU in 3 oz), Egg yolks (41 IU per egg), Canned fish (154 IU in 3 oz tuna, 270 IU in 3.5 oz sardines), Shiitake mushrooms (40 IU in 1 cup).
- Fortified foods (including infant formula milk): Milk: whole, nonfat or reduced fat (100 IU in 8 oz), Yogurt (80–100 IUs in 6 oz), Almond milk (100 IU in 8 oz), Pudding made with milk (49-60 IUs in ½ cup), Orange juice (137 IU in 1 cup), Breakfast cereals (50–100 IUs in 0.75–1 cup), Fortified tofu (80 IU in 3 oz), Oatmeal (150 IU in 1 packet), Cheese (40 IU in 1 slice), Eggnog (123 IU in 8 oz, Margarine (25 IU in 1 teaspoon).
- Supplements: Ergocalciferol (vitamin D2), Cholecalciferol (vitamin D3)
They also refer to average intakes over a period of time, such as a week, and take account of day-to-day variations in intake.
SACN’s review concluded that these at-risk groups include people whose skin has little or no exposure to the sun, like those in care homes, or people who cover their skin when they are outside.
Vitamin D & Your Body
Regular intake of Vitamin D is Essential:
- To protect musculoskeletal health. Vitamin D status has been found to be related with a number of non-skeletal diseases. In addition to the well-known effects on musculoskeletal health, vitamin D status may be related to a number of non-skeletal diseases. Recent meta-analyses concluded that vitamin D must be administered in combination with calcium in order to substantially reduce the risk of nonvertebral fracture in adults over the age of 50 years. Fracture protection is optimal when patient adherence to medication exceeds 80% and vitamin D doses exceed 700 IU/day. In addition to disordered calcium homeostasis, low vitamin D levels might have effects on cell proliferation and differentiation and immune function.
- Cancer: The high prevalence of vitamin D deficiency, combined with the discovery of increased risks of certain types of cancer in those who are deficient, suggest that vitamin D deficiency may account for several thousand premature deaths from colon, breast, ovarian, and prostate cancer annually. This discovery creates a new impetus for ensuring adequate vitamin D intake in order to reduce the risk of cancer.
- Multiple Sclerosis: Certain cells in the immune and nervous systems have receptors for vitamin D. Receptors are found on the surface of a cell where they receive chemical signals. By attaching themselves to a receptor, these chemical signals direct a cell to do something, for example, to act in a certain way, or to divide or die. The vitamin D receptors on nerve and immune system cells mean that vitamin D is somehow affecting the cell. When immune system cells are exposed to vitamin D in laboratory experiments, they become less inflamed. This could mean that vitamin D affects the immune system and makes it less likely to attack other cells in the body. Some researchers believe that this means vitamin D has the potential to prevent MS from developing. It could also affect relapsing remitting MS by reducing the number of relapses and how severe they are. Research has found that those who get more sun exposure early and throughout life have lower chances of developing MS. Whether this is because they produce more vitamin D and that’s what helps prevent MS, or whether the sun is helping for some other reason, researchers don’t know for sure. The Maastricht University in the Netherlands suggests that for people who already have MS, vitamin D may lessen the frequency and severity of their symptoms.
- Cardiovascular disease. Vitamin D receptors have been found in all the major cardiovascular cell types including cardiomyocytes, arterial wall cells, and immune cells. Experimental studies have established a role for vitamin D metabolites in pathways that are integral to cardiovascular function and disease, including inflammation, thrombosis, and the renin–angiotensin system.
Vitamin D may lower the risk of CHD incidence and death by reducing:
- Thickening of the arterial walls
- Metabolic diseases such as diabetes and high blood pressure
- Risk of respiratory infections
- Risk of arterial calcification or hardening.