To explore the association between vitamin B12 (B12)-containing supplement use, low B12 concentrations and biochemically defined B12 deficiency in US adults.

A cross-sectional study with adjustment for survey design. Prevalence ratios for two age groups (18–50 and >50 years) were estimated using unconditional logistic models. Outcome measures included prevalence of low serum B12 concentration (<148 pmol/l) and biochemical B12 deficiency (serum B12 < 148 pmol/l with concomitant homocysteine > 10 μmol/l).

A population survey of health and nutritional measures.

Subjects were non-institutionalized adults, aged 18 years and older, who participated in Phase 2 of NHANES III (Third National Health and Nutrition Examination Survey).

Low B12 concentrations were less prevalent among persons consuming B12-containing supplements (P = 0·001) with an adjusted prevalence ratio of 0·6 (95 % CI 0·3, 1·0). Biochemical B12 deficiency showed a similar trend (P = 0·0002), with an adjusted prevalence ratio of 0·3 (95 % CI 0·1, 0·8). Prevalence ratios were similar in adults >50 years of age, although the prevalence of low B12 and biochemical deficiency was proportionally higher.

Consumption of B12-containing supplements was associated with at least 50 % lower prevalence of both low serum B12 and biochemical B12 deficiency in a nationally representative sample of US adults, suggesting increased consumption of B12 from supplements or from fortified foods may reduce the prevalence of B12 deficiency. Additionally, the current Recommended Daily Allowance for B12 of 2·4 μg may be insufficient for those aged >50 years.

To estimate the impact of foetal nutritional status on cardiovascular risk among children with the Foetal Nutritional Status Index (FNSI), calculated by dividing the child's birth weight (BW, kg) by the mother's height (m2).

Cross-sectional survey analysis.

A sample of children from the US Third National Health and Nutrition Examination Survey.

A total of 3109 children who were 5–11 years of age and had data on BW and mother's height. Non-fasting blood samples were included.

Overall, the FNSI was positively associated with BW and negatively associated with mother's height (P < 0.0001). Within sex-specific quintiles of FNSI (third quintile as reference) adjusted for potential confounding variables, cardiovascular risk factors tended to be ‘higher’ in the lower quintiles for males while the opposite was true for females. Multivariate logistic regression analyses indicated that the odds for males in quintile 1 was 2.4 for having a low level of high-density lipoprotein cholesterol (P < 0.01) and 2.1 for having a cluster of cardiovascular risk factors (P = 0.01); for females, the odds of having a cluster of cardiovascular risk factors was approximately two times higher for those in the first and fifth quintiles, who also had a significantly higher prevalence of central obesity.

The FNSI may be a potential proxy indicator of foetal nutritional status and it may be used to test specific hypotheses of whether foetal nutrition restriction or overnutrition programmes future cardiovascular risk.

This study examined dietary intakes and nutritional status of marijuana users and non-current marijuana users in US adults aged 20 to 59 years.

We used data from the Third National Health and Nutrition Examination Survey (NHANES III), 1988–1994. Information on self-reported drug use, including marijuana, was obtained as part of the NHANES III physical examination component. Nutritional status was assessed using height and weight, and blood biochemistries. Dietary intake was assessed using a 24-hour recall and a food-frequency questionnaire.

Among adults 20–59 years of age, 45% reported ever having used marijuana in their lifetime. A total of 8.7% reported using marijuana in the past month. Current marijuana users had higher intakes of energy and nutrients than non-current marijuana users; however, body mass index (BMI) was slightly lower. We found higher cigarette-smoking rates and higher consumption of sodas and alcohol, specifically beer, among marijuana users than among non-current marijuana users. Marijuana users also consumed more sodium, fewer fruits, and more pork, cheese, and salty snacks. Nutritional status, using indicators of serum nutrients, serum albumin, haematocrit and haemoglobin, was similar between marijuana users and non-current marijuana users. Serum carotenoid levels were lower among marijuana users, independent of cigarette smoking.

Dietary intake was different among marijuana users than among non-current marijuana users. Although overall nutritional status was similar, serum carotenoid levels were lower in marijuana users. The long-term health effects of these differences in marijuana users deserve careful consideration in future research.

Results of previous studies on diet and gallbladder disease (GBD), defined as having gallstones or having had surgery for gallstones, have been inconsistent. This research examined patterns of food intake in Mexican Americans and their associations with GBD.

Cross-sectional.

The study population included 4641 Mexican Americans aged 20–74 years who participated in the 1988–94 third National Health and Nutrition Examination Survey (NHANES III). GBD was diagnosed by ultrasound. Food intake patterns were identified by principal components analysis based on food frequency questionnaire responses. Component scores representing the level of intake of each pattern were categorized into quartiles, and prevalence odds ratios (POR) were estimated relative to the lowest quartile along with 95% confidence intervals (CI).

There were four distinct patterns in women (vegetable, high calorie, traditional, fruit) and three in men (vegetable, high calorie, traditional). After age adjustment, none were associated with GBD in women. However, men in the third (POR = 0.42, 95%CI 0.21–0.85) and fourth (POR = 0.53, 95%CI 0.28–1.01) quartiles of the traditional intake pattern were half as likely to have GBD as those in the lowest quartile.

These findings add to a growing literature suggesting dietary intake patterns can provide potentially useful and relevant information on diet–disease associations. Nevertheless, methods to do so require further development and validation.