Public Health Recommendations

In 2010, the Institute of Medicine at the National Academy of Sciences established revised Dietary Reference Intake (DRI) recommendations for vitamin D based on new research in this area. The following Adequate Intake (AI) levels for vitamin D were established in 2010 for infants:

• Infants 0-6 months: 10 micrograms (400 IU) per day
• Infants 6-12 months: 10 micrograms (400 IU) per day

The following Recommended Dietary Allowances (RDAs) were established for children, teenagers, and adults:

• Children 1-13 years: 15 micrograms (600 IU)
• Teenagers 14-18 years: 15 micrograms (600 IU)
• Adults 19-70 years: 15 micrograms (600 IU)
• Adults above 70 years: 20 micrograms (800 IU)
• Pregnant and lactating women: 15 micrograms (600 IU)

While we were glad to see the the National Academy of Sciences making revised public health recommendations in 2010 for increased intake of vitamin D, we do not believe that all health and lifestyle factors evaluated in research studies on vitamin D research were fully addressed in the revised recommendations. Over the past 15 years, more than 10,000 studies on vitamin D have been published in research journals. These studies have convincingly shown that: (1) we need much more vitamin D than we previously thought; (2) lifestyle trends have significantly reduced our exposure to sunlight; (3) prevalence of vitamin D deficiency is far greater than previously estimated, and (4) more vitamin D is required to remedy deficiency than can be obtained in a standard diet.

In studies on infants and toddlers, between 40-65% have been shown to be vitamin D insufficient with blood levels of hydroxyvitamin D below 30 ng/mL in several countries throughout the world, and in studies in the U.S., including a recent study in Massachusetts. Insufficiency has also been shown in U.S. teens, at a level of approximately 60% (once again, using the standard of 30 ng/mL or less for hydroxyvitamin D in the blood). Similar percentages have been determined for insufficiency in older individuals. Among young adults and middle-aged individuals, the prevalence of vitamin D insufficiency has been estimated to range from a minimum of about 50% to a maximum of perhaps 75% or greater. It�s important to note that �insufficiency� is a looser standard than �deficiency� and generally refers to a blood level of hydroxyvitamin D below 30 ng/mL rather than a blood level below 20 ng/mL. While this lower blood level has traditionally been used to diagnose vitamin D deficiency, it is no longer appears relevant for determining the amount of vitamin D needed for optimal hormonal regulation of many body processes by vitamin D. Realization of this greater level of vitamin D needed in our bloodstream is one result of the revolution that has taken place in our understanding of vitamin D over the past 15 years.

Just as we now realize that more vitamin D is needed in our blood, we also realize that it takes higher levels of vitamin D intake to bring blood levels up to a healthy standard. For example, in situations where sunlight is limited, we know that at least 1,000 IU of vitamin D are needed to increase blood levels of vitamin D from 20ng/mL to 30 ng/mL or higher. For prevention of bone loss in persons at risk for osteoporosis, we know that a minimum of 700 IU is required and that no prevention results have been demonstrated at levels of intake below 400 IU. Under circumstances involving autoimmune problems like rheumatoid arthritis or multiple sclerosis, experimental supplemental doses of vitamin D range not in 100s of IUs, but in 1,000s or 10,000s of IUs.

Since personal health history and personal exposure to sunlight play such an important role in determining each individual's vitamin D needs, it is very difficult to make a firm and fast public health recommendation for vitamin D that is guaranteed to meet the optimal requirements of each individual. For this reason, we like the basic two-fold approach taken by the Harvard School of Public Health, which can be found here.

On a first level, even though there is not yet conclusive research evidence available, daily supplementation with vitamin D in the range of 1,000 - 2,000 IU may provide important health benefits for many individuals. If your routine diet does not include plentiful amounts of vitamin D-rich foods, you may want to target the higher side of this range (while also increasing your intake of D-rich foods). If your diet already includes ample amounts of foods that are rich in vitamin D, you may want to target the lower side of this range when deciding on a supplementation level.

On a second level, if you are an individual who might be at higher risk for vitamin D deficiency (for example, because you have very limited exposure to sunlight), we encourage you to consult with your healthcare provider, schedule a blood test for vitamin D, and determine (in consultation with your healthcare provider) an appropriate level of vitamin D supplementation. Depending on the results of your blood test, you may very possibly need a greater level of vitamin D supplementation that is greater than the 4,000 IU Tolerable Upper Limit set by the National Academy of Sciences. Blood testing can definitely help to remove the "guesswork" factor here. You'll be able to determine the actual level of hydroxyvitamin D in your blood and see the actual amount of increase following supplementation at whatever level you and your healthcare provider determine to be appropriate. When supplementing with vitamin D, we support the position of the Harvard School of Public Health (and many other public health organizations) in recommending supplementation with vitamin D3 (cholecalciferol) rather than D2 (ergocalciferol)."

What is our bottom line with respect to food versus supplemental intake of vitamin D? Based on studies showing the impact of supplemental D3 intake on blood levels of hydroxyvitamin D, we believe that the vast majority of U.S. adults and children will not be able to achieve optimal vitamin D status from food intake alone. Exactly how much D3 supplementation each individual may need�and the form of this supplementation�should be determined with the help of a healthcare provider. That healthcare provider can not only evaluate personal health history factors but can also monitor the impact of vitamin D supplementation of blood levels of this vitamin.

Despite this likely need for supplemental vitamin D, we also believe that it is important to maximize food intake of vitamin D. Intake of foods rich in vitamin D still remains a natural lifestyle option for obtaining this vitamin, even if this option is not sufficient all by itself to offset lack of sunlight exposure and other factors that have combined to compromise our vitamin D status.

With respect to women who are breastfeeding, the American Academy of Pediatrics (AAP) and the Canadian Pediatric Society (CPS) have both recommended vitamin D supplementation for both mothers and infants. The APP has recommended 200 IU of vitamin D per day for all infants 2 months and older, and 400 IU for newborns during the first days of life. These APP recommendations are generally consistent with the revised 2010 Adequate Intake (AI) levels for vitamin D set by the National Academy of Sciences (NAS). The NAS recommends 400 IU of vitamin D for newborns and infants up to 12 months of age. It is worth pointing out that direct vitamin D supplementation for the infant is separate and apart from any vitamin D supplementation that the mother herself might need. Given the special challenges posed by breastfeeding for vitamin D sufficiency, the guidance of a healthcare provider is highly recommended to determine the steps needed for optimal vitamin D intake in this situation. Like breastfeeding, pregnancy poses a special challenge for vitamin D sufficiency. Once again, given the widespread nature of vitamin D deficiency, the DRIs may be unable to provide optimal guidelines for many pregnant women. For this reason, pregnant women are encouraged to work out a vitamin D sufficiency plan with their healthcare provider.

The National Academy of Sciences set Tolerable Upper Intake Levels (ULs) for vitamin D as follows:

• infants, 0-6 months: 25 micrograms (1,000 IU) per day
• infants, 6-12 months: 38 micrograms (1,500 IU) per day
• children, 1-3 years: 63 micrograms (2,500 IU) per day
• children, 4-8 year: 75 micrograms (3,000 IU)per day
• children and adolescents, 9-18 years: 100 micrograms (4,000 IU) per day
• adults, 19 years and older: 100 micrograms (4,000 IU) per day
• pregnant and lactating women, 100 micrograms (4,000 IU) per day.

For more details on this, see the Toxicity Symptoms section above.

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